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Head-to-head comparison

Claude Sonnet 5 vs. DeepSeek-V4-Flash

Compare published benchmark results from matching versions and cohorts, API pricing, and technical specifications. Any documented test setup differences remain visible.

shared result series
58
distinct benchmarks
1
latest retrieval
2026-09-04

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Specifications

General specifications

Release date, availability, context window, architecture, and published parameter counts at a glance. Undisclosed details remain marked as unavailable.

Specifications for Claude Sonnet 5 and DeepSeek-V4-Flash
AttributeClaude Sonnet 5DeepSeek-V4-Flash
ProviderAnthropicDeepSeek
ReleasedJun 30, 2026Apr 24, 2026
AvailabilityActivePreview
Model typeProprietaryOpen Weights
ParametersNot published284B, 13B active
ArchitectureNot publishedMixture of Experts
Context window1,000,000 tokens1,000,000 tokens
Knowledge cutoffJanuary 2026Not published
Technical sourcesModel, ContextModel

Pricing

API pricing compared

The table compares official standard API rates per 1M tokens, including published cache pricing. Batch, fast, priority, regional surcharges, tool calls, and cloud platform pricing are excluded.

API pricing for Claude Sonnet 5 and DeepSeek-V4-Flash
Price typeClaude Sonnet 5DeepSeek-V4-Flash
API input$2$0.14
API output$10$0.28
Cache read$0.2$0.
Cache write (5 min.)$2.5Not listed
Cache write (1 hr.)$4Not listed
Price verified09/02/2026 Source07/30/2026 Source
Claude Sonnet 5DeepSeek-V4-Flash
API inputUSD per 1M tokens, base tier
Claude Sonnet 5$2
DeepSeek-V4-FlashLower price$0.14
API outputUSD per 1M tokens, base tier
Claude Sonnet 5$10
DeepSeek-V4-FlashLower price$0.28
Cache readUSD per 1M tokens, base tier
Claude Sonnet 5$0.2
DeepSeek-V4-FlashLower price$0.003

Key to the marks:better valuebetter, but not conclusivetie

Pricing by provider

Direct developer pricing and provider endpoint tariffs routed through OpenRouter are listed separately. Prices are in USD per 1M tokens. Context-dependent direct tiers plus regional, Flex, Priority, and other OpenRouter tariffs remain individually identifiable.

Provider pricing for Claude Sonnet 5 and DeepSeek-V4-Flash
ModelProviderPurchase route and tariffInput per 1M tokensOutput per 1M tokensSource
Claude Sonnet 5AnthropicDirect from developerStandard APILowest listed price: $2Lowest listed price: $10Source09/02/2026
Amazon BedrockVia OpenRouteramazon-bedrock/globalLowest listed price: $2Lowest listed price: $10Source09/07/2026
Amazon BedrockVia OpenRouteramazon-bedrock/us-east-1$2.2$11Source09/07/2026
AnthropicVia OpenRouteranthropicLowest listed price: $2Lowest listed price: $10Source09/07/2026
AzureVia OpenRouterazure/globalLowest listed price: $2Lowest listed price: $10Source09/07/2026
AzureVia OpenRouterazure/usLowest listed price: $2Lowest listed price: $10Source09/07/2026
Claude Platform on AWSVia OpenRouterclaude-on-awsLowest listed price: $2Lowest listed price: $10Source09/07/2026
GoogleVia OpenRoutergoogle-vertex/europe$2.2$11Source09/07/2026
GoogleVia OpenRoutergoogle-vertex/globalLowest listed price: $2Lowest listed price: $10Source09/07/2026
GoogleVia OpenRoutergoogle-vertex/us$2.2$11Source09/07/2026
DeepSeek-V4-FlashDeepSeekDirect from developerStandard API$0.14$0.28Source07/30/2026
AlibabaVia OpenRouteralibaba$0.352$1.056Source09/07/2026
AtlasCloudVia OpenRouteratlas-cloud/fp4$0.44$1.32Source09/07/2026
BaiduVia OpenRouterbaidu/fp8$0.14$0.28Source09/07/2026
BaseTenVia OpenRouterbaseten/fp8#1$0.13$0.26Source09/07/2026
BaseTenVia OpenRouterbaseten/fp8#2$0.13$0.26Source09/07/2026
CloudflareVia OpenRoutercloudflare$0.44$1.32Source09/07/2026
CoreWeaveVia OpenRoutercoreweave/fp8$0.13$0.28Source09/07/2026
DeepInfraVia OpenRouterdeepinfra/fp8$0.06$0.18Source09/07/2026
DeepSeekVia OpenRouterdeepseek$0.22$0.66Source09/07/2026
DigitalOceanVia OpenRouterdigitalocean$0.08$0.252Source09/07/2026
FireworksVia OpenRouterfireworks$0.22$0.66Source09/07/2026
GMICloudVia OpenRoutergmicloud/fp8$0.352$1.056Source09/07/2026
InceptronVia OpenRouterinceptron/fp4$0.13$0.28Source09/07/2026
MakoraVia OpenRoutermakora$0.09$0.195Source09/07/2026
Mancer 2Via OpenRoutermancer/fp8$0.15$0.5Source09/07/2026
MorphVia OpenRoutermorph/bf16$0.1234$0.3475Source09/07/2026
NextBitVia OpenRouternextbit/fp8$0.4$1.2Source09/07/2026
NovitaVia OpenRouternovita/fp8$0.4092$1.2276Source09/07/2026
OpenInferenceVia OpenRouteropen-inference/fp8$0.05$0.16Source09/07/2026
ParasailVia OpenRouterparasail/fp8$0.14$0.28Source09/07/2026
PhalaVia OpenRouterphala$0.44$1.32Source09/07/2026
RekaVia OpenRouterreka/fp4$0.11$0.66Source09/07/2026
RelaceVia OpenRouterrelace/fp4Lowest listed price: $0.045Lowest listed price: $0.09Source09/07/2026
Sail ResearchVia OpenRoutersail-research/fp4$0.065$0.18Source09/07/2026
SiliconFlowVia OpenRoutersiliconflow/fp8$0.22$0.66Source09/07/2026
StreamLakeVia OpenRouterstreamlake/fp8$0.088$0.264Source09/07/2026
TogetherVia OpenRoutertogether$0.14$0.28Source09/07/2026
VeniceVia OpenRoutervenice$0.175$0.35Source09/07/2026
WaferVia OpenRouterwafer/fast$0.1$0.25Source09/07/2026

Performance

Shared benchmarks

Only published results with the same benchmark version, task, metric, and comparison cohort are paired. Different reasoning levels, agents, harnesses, or output limits appear directly in the table.

Capability profile from matched benchmarks

Each axis averages directly matched benchmark families. A value of 100 means the stronger value within this pair, not a universal quality score.

255075100CodingReasoningMathematicsKnowledgeFinanceLegalHealthGeneral
Claude Sonnet 5
DeepSeek-V4-Flash
Coding: 100 / 97.3 (1 benchmark family)
Reasoning: 100 / 97.6 (1 benchmark family)
Mathematics: 100 / 97.4 (1 benchmark family)
Knowledge: 100 / 97.8 (1 benchmark family)
Finance: 100 / 98.1 (1 benchmark family)
Legal: 100 / 98.5 (1 benchmark family)
Health: 100 / 99 (1 benchmark family)
General: 100 / 98.1 (1 benchmark family)

29 matched rows from 1 benchmark families were considered. The radar shows 8 of 8 comparable categories.

Claude Sonnet 5DeepSeek-V4-Flash
LMArena Text, Style ControlOverall. Higher is better. Test setup not documented as identical
Claude Sonnet 5Higher measured value1,462.16
DeepSeek-V4-Flash1,435.816
LMArena Text, Style ControlOverall. Higher is better. No documented setup difference
Claude Sonnet 5Winner1,462.16
DeepSeek-V4-Flash1,438.462
LMArena Text, Style ControlBusiness, management and finance. Higher is better. Test setup not documented as identical
Claude Sonnet 5Higher measured value1,462.981
DeepSeek-V4-Flash1,437.854
LMArena Text, Style ControlBusiness, management and finance. Higher is better. No documented setup difference
Claude Sonnet 5Winner1,462.981
DeepSeek-V4-Flash1,434.968
LMArena Text, Style ControlChinese. Higher is better. Test setup not documented as identical
Claude Sonnet 5Higher measured value1,499.492
DeepSeek-V4-Flash1,472.677
LMArena Text, Style ControlChinese. Higher is better. No documented setup difference
Claude Sonnet 5No clear lead1,499.492
DeepSeek-V4-Flash1,479.62
LMArena Text, Style ControlCoding. Higher is better. Test setup not documented as identical
Claude Sonnet 5Higher measured value1,520.647
DeepSeek-V4-Flash1,483.101
LMArena Text, Style ControlCoding. Higher is better. No documented setup difference
Claude Sonnet 5Winner1,520.647
DeepSeek-V4-Flash1,479.449
LMArena Text, Style ControlCreative writing. Higher is better. Test setup not documented as identical
Claude Sonnet 5Higher measured value1,437.519
DeepSeek-V4-Flash1,408.18
LMArena Text, Style ControlCreative writing. Higher is better. No documented setup difference
Claude Sonnet 5Winner1,437.519
DeepSeek-V4-Flash1,408.903
LMArena Text, Style ControlEnglish. Higher is better. Test setup not documented as identical
Claude Sonnet 5Higher measured value1,473.71
DeepSeek-V4-Flash1,445.287
LMArena Text, Style ControlEnglish. Higher is better. No documented setup difference
Claude Sonnet 5Winner1,473.71
DeepSeek-V4-Flash1,449.894

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for Claude Sonnet 5 and DeepSeek-V4-Flash
Benchmark and taskClaude Sonnet 5DeepSeek-V4-FlashSource
LMArena Text, Style ControlOverall
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 31,096 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 48,963 anonymous pairwise votes.
Higher measured value1,462.16
95% confidence interval: ±4.745The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,435.816
95% confidence interval: ±4.15The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlOverall
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 31,096 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 48,705 anonymous pairwise votes.
Winner1,462.16
95% confidence interval: ±4.745The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,438.462
95% confidence interval: ±4.21The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlBusiness, management and finance
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 6,214 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 9,911 anonymous pairwise votes.
Higher measured value1,462.981
95% confidence interval: ±8.229The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,437.854
95% confidence interval: ±7.128The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlBusiness, management and finance
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 6,214 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 10,060 anonymous pairwise votes.
Winner1,462.981
95% confidence interval: ±8.229The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,434.968
95% confidence interval: ±7.142The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlChinese
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 2,074 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 2,530 anonymous pairwise votes.
Higher measured value1,499.492
95% confidence interval: ±13.64The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,472.677
95% confidence interval: ±12.483The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlChinese
Test details
No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 2,074 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 2,509 anonymous pairwise votes.
No clear lead1,499.492
95% confidence interval: ±13.64The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,479.62
95% confidence interval: ±12.459The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlCoding
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 8,576 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 14,346 anonymous pairwise votes.
Higher measured value1,520.647
95% confidence interval: ±7.348The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,483.101
95% confidence interval: ±6.376The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlCoding
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 8,576 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 14,310 anonymous pairwise votes.
Winner1,520.647
95% confidence interval: ±7.348The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,479.449
95% confidence interval: ±6.409The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlCreative writing
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 6,087 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 7,972 anonymous pairwise votes.
Higher measured value1,437.519
95% confidence interval: ±8.524The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,408.18
95% confidence interval: ±7.747The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlCreative writing
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 6,087 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 8,029 anonymous pairwise votes.
Winner1,437.519
95% confidence interval: ±8.524The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,408.903
95% confidence interval: ±7.781The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlEnglish
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 13,422 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 21,931 anonymous pairwise votes.
Higher measured value1,473.71
95% confidence interval: ±6.123The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,445.287
95% confidence interval: ±5.383The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlEnglish
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 13,422 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 21,747 anonymous pairwise votes.
Winner1,473.71
95% confidence interval: ±6.123The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,449.894
95% confidence interval: ±5.421The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlEntertainment, sports and media
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 7,751 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 10,423 anonymous pairwise votes.
Higher measured value1,432.479
95% confidence interval: ±7.757The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,405.349
95% confidence interval: ±7.122The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlEntertainment, sports and media
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 7,751 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 10,655 anonymous pairwise votes.
Winner1,432.479
95% confidence interval: ±7.757The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,406.152
95% confidence interval: ±7.06The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlExcluding ties
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 23,349 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 36,983 anonymous pairwise votes.
Higher measured value1,467.502
95% confidence interval: ±6.142The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,431.271
95% confidence interval: ±5.416The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlExcluding ties
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 23,349 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 37,039 anonymous pairwise votes.
Winner1,467.502
95% confidence interval: ±6.142The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,435.7
95% confidence interval: ±5.462The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlExpert prompts
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 3,376 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 4,904 anonymous pairwise votes.
Higher measured value1,510.217
95% confidence interval: ±10.682The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,458.425
95% confidence interval: ±9.147The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlExpert prompts
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 3,376 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 4,907 anonymous pairwise votes.
Winner1,510.217
95% confidence interval: ±10.682The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,467.744
95% confidence interval: ±9.211The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlFrench
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 1,079 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 1,909 anonymous pairwise votes.
Higher measured value1,484.457
95% confidence interval: ±19.668The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,444.246
95% confidence interval: ±15.542The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlFrench
Test details
No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 1,079 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 1,872 anonymous pairwise votes.
No clear lead1,484.457
95% confidence interval: ±19.668The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,457.512
95% confidence interval: ±15.76The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlGerman
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 502 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 834 anonymous pairwise votes.
Higher measured value1,477.479
95% confidence interval: ±27.12The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,423.985
95% confidence interval: ±21.432The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlGerman
Test details
No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 502 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 881 anonymous pairwise votes.
No clear lead1,477.479
95% confidence interval: ±27.12The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,434.001
95% confidence interval: ±20.992The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlHard prompts
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 20,640 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 32,576 anonymous pairwise votes.
Higher measured value1,490.094
95% confidence interval: ±5.487The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,459.19
95% confidence interval: ±4.879The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlHard prompts
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 20,640 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 32,479 anonymous pairwise votes.
Winner1,490.094
95% confidence interval: ±5.487The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,458.492
95% confidence interval: ±4.934The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlHard prompts, English
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 8,973 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 15,327 anonymous pairwise votes.
Higher measured value1,497.22
95% confidence interval: ±7.16The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,464.306
95% confidence interval: ±6.191The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlHard prompts, English
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 8,973 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 15,135 anonymous pairwise votes.
Winner1,497.22
95% confidence interval: ±7.16The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,465.194
95% confidence interval: ±6.261The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlInstruction following
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 10,907 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 16,772 anonymous pairwise votes.
Higher measured value1,465.887
95% confidence interval: ±6.647The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,428.139
95% confidence interval: ±5.955The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlInstruction following
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 10,907 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 16,813 anonymous pairwise votes.
Winner1,465.887
95% confidence interval: ±6.647The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,433.908
95% confidence interval: ±6.024The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlJapanese
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 460 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 633 anonymous pairwise votes.
Higher measured value1,450.323
95% confidence interval: ±28.849The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,397.389
95% confidence interval: ±25.351The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlJapanese
Test details
No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 460 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 600 anonymous pairwise votes.
No clear lead1,450.323
95% confidence interval: ±28.849The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,422.217
95% confidence interval: ±25.99The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlKorean
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 569 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 867 anonymous pairwise votes.
Higher measured value1,426.245
95% confidence interval: ±25.783The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,394.225
95% confidence interval: ±21.434The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlKorean
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 569 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 909 anonymous pairwise votes.
Winner1,426.245
95% confidence interval: ±25.783The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,374.943
95% confidence interval: ±21.551The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlLegal and government
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 2,686 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 3,892 anonymous pairwise votes.
Higher measured value1,480.894
95% confidence interval: ±12.038The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,449.174
95% confidence interval: ±10.185The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlLegal and government
Test details
No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 2,686 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 3,872 anonymous pairwise votes.
No clear lead1,480.894
95% confidence interval: ±12.038The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,459.091
95% confidence interval: ±10.242The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlLife, physical and social science
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 5,123 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 7,776 anonymous pairwise votes.
Higher measured value1,487.544
95% confidence interval: ±8.817The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,458.608
95% confidence interval: ±7.61The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlLife, physical and social science
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 5,123 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 7,968 anonymous pairwise votes.
Winner1,487.544
95% confidence interval: ±8.817The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,460.882
95% confidence interval: ±7.588The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlLonger queries
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 14,382 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 21,561 anonymous pairwise votes.
Higher measured value1,482.113
95% confidence interval: ±6.3The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,448.456
95% confidence interval: ±5.733The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlLonger queries
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 14,382 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 21,664 anonymous pairwise votes.
Winner1,482.113
95% confidence interval: ±6.3The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,449.036
95% confidence interval: ±5.731The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlMath
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 1,355 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 2,516 anonymous pairwise votes.
Higher measured value1,473.628
95% confidence interval: ±15.97The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,425.091
95% confidence interval: ±12.209The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlMath
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 1,355 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 2,459 anonymous pairwise votes.
Winner1,473.628
95% confidence interval: ±15.97The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,441.301
95% confidence interval: ±12.311The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlMathematical professions
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 1,635 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 2,746 anonymous pairwise votes.
Higher measured value1,487.105
95% confidence interval: ±14.914The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,431.608
95% confidence interval: ±11.935The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlMathematical professions
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 1,635 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 2,607 anonymous pairwise votes.
Winner1,487.105
95% confidence interval: ±14.914The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,443.348
95% confidence interval: ±12.313The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlMedicine and healthcare
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 2,269 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 3,429 anonymous pairwise votes.
Higher measured value1,478.121
95% confidence interval: ±13.327The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,459.604
95% confidence interval: ±10.945The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlMedicine and healthcare
Test details
No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 2,269 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 3,495 anonymous pairwise votes.
No clear lead1,478.121
95% confidence interval: ±13.327The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,462.945
95% confidence interval: ±10.866The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlMulti-turn
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 5,435 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 8,820 anonymous pairwise votes.
Higher measured value1,471.179
95% confidence interval: ±8.759The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,452.356
95% confidence interval: ±7.462The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlMulti-turn
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 5,435 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 8,674 anonymous pairwise votes.
Winner1,471.179
95% confidence interval: ±8.759The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,445.683
95% confidence interval: ±7.508The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlNon-English
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 17,674 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 27,030 anonymous pairwise votes.
Higher measured value1,447.544
95% confidence interval: ±5.655The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,423.067
95% confidence interval: ±5.056The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlNon-English
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 17,674 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 26,956 anonymous pairwise votes.
Winner1,447.544
95% confidence interval: ±5.655The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,422.651
95% confidence interval: ±5.123The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlPolish
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 491 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 1,005 anonymous pairwise votes.
Higher measured value1,440.102
95% confidence interval: ±26.329The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,439.462
95% confidence interval: ±18.965The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlPolish
Test details
No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 491 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 1,014 anonymous pairwise votes.
No clear lead1,440.102
95% confidence interval: ±26.329The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,430.358
95% confidence interval: ±18.866The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlRussian
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 3,153 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 5,250 anonymous pairwise votes.
Higher measured value1,471.763
95% confidence interval: ±10.923The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,433.186
95% confidence interval: ±8.845The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlRussian
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 3,153 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 5,207 anonymous pairwise votes.
Winner1,471.763
95% confidence interval: ±10.923The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,437.38
95% confidence interval: ±8.983The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlSoftware and IT services
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 12,308 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 20,105 anonymous pairwise votes.
Higher measured value1,504.552
95% confidence interval: ±6.385The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,471.075
95% confidence interval: ±5.634The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlSoftware and IT services
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 12,308 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 20,031 anonymous pairwise votes.
Winner1,504.552
95% confidence interval: ±6.385The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,473.269
95% confidence interval: ±5.664The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlSpanish
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 907 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 1,548 anonymous pairwise votes.
Higher measured value1,453.407
95% confidence interval: ±20.651The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,433.026
95% confidence interval: ±16.368The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlSpanish
Test details
No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 907 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 1,443 anonymous pairwise votes.
No clear lead1,453.407
95% confidence interval: ±20.651The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,431.772
95% confidence interval: ±16.888The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlWriting, literature and language
Test details
Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 8,238 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 11,742 anonymous pairwise votes.
Higher measured value1,451.744
95% confidence interval: ±7.447The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,417.982
95% confidence interval: ±6.712The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026
LMArena Text, Style ControlWriting, literature and language
Test details
No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Sonnet 5: Snapshot: claude-sonnet-5-high, Reasoning: high, Harness: Arena text, style control
DeepSeek-V4-Flash: Snapshot: deepseek-v4-flash-high-preview, Reasoning: high, Harness: Arena text, style controlClaude Sonnet 5: Style-controlled Arena rating from 8,238 anonymous pairwise votes.DeepSeek-V4-Flash: Style-controlled Arena rating from 11,861 anonymous pairwise votes.
Winner1,451.744
95% confidence interval: ±7.447The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.
1,421.395
95% confidence interval: ±6.717The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.		LMArena
Source details
Data as of: 09/01/2026

Key to the marks:better valuebetter, but not conclusivetie

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