Head-to-head comparison

Claude Opus 5 vs. DeepSeek-V4.1-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: 24
distinct benchmarks: 24
latest retrieval: 2026-09-29

First modelSecond model

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 Opus 5 and DeepSeek-V4.1-Flash
Attribute	Claude Opus 5	DeepSeek-V4.1-Flash
Provider	Anthropic	DeepSeek
Released	Jul 24, 2026	Sep 10, 2026
Availability	Active	Active
Model type	Proprietary	Open Weights
Parameters	Not published	552B
Architecture	Not published	Mixture of Experts
Context window	1,000,000 tokens	1,000,000 tokens
Knowledge cutoff	May 2026	Not published
Technical sources	Model, Knowledge cutoff	Model

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 Opus 5 and DeepSeek-V4.1-Flash
Price type	Claude Opus 5	DeepSeek-V4.1-Flash
API input	$5	$0.15 (Off-Peak)
API output	$25	$0.6 (Off-Peak)
Cache read	$0.5	$0. (Off-Peak)
Cache write (5 min.)	$6.25	Not listed
Cache write (1 hr.)	$10	Not listed
Price verified	09/22/2026 Source	09/23/2026 Source
DeepSeek-V4.1-Flash: peak pricing is $0.3 input / $1.2 output per 1M tokens during Mon, Tue, Wed, Thu, Fri, 01:00-04:00 UTC; Mon, Tue, Wed, Thu, Fri, 06:00-10:00 UTC; off-peak rates apply at all other times.

Claude Opus 5DeepSeek-V4.1-Flash

API inputUSD per 1M tokens, base tier

Claude Opus 5$5

DeepSeek-V4.1-Flash$0.15

API outputUSD per 1M tokens, base tier

Claude Opus 5$25

DeepSeek-V4.1-Flash$0.6

Cache readUSD per 1M tokens, base tier

Claude Opus 5$0.5

DeepSeek-V4.1-Flash$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 Opus 5 and DeepSeek-V4.1-Flash
Model	Provider	Purchase route and tariff	Input per 1M tokens	Output per 1M tokens	Source
Claude Opus 5	Anthropic	Direct from developerStandard API	Lowest listed price: $5	Lowest listed price: $25	Source09/22/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock	Lowest listed price: $5	Lowest listed price: $25	Source10/06/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock/eu-west-1	$5.5	$27.5	Source10/06/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock/us-east-1	$5.5	$27.5	Source10/06/2026
	Anthropic	Via OpenRouteranthropic	Lowest listed price: $5	Lowest listed price: $25	Source10/06/2026
	Anthropic	Via OpenRouteranthropic/fast	$10	$50	Source10/06/2026
	Azure	Via OpenRouterazure/global	Lowest listed price: $5	Lowest listed price: $25	Source10/06/2026
	Azure	Via OpenRouterazure/us	$5.5	$27.5	Source10/06/2026
	Claude Platform on AWS	Via OpenRouterclaude-on-aws	Lowest listed price: $5	Lowest listed price: $25	Source10/06/2026
	Google	Via OpenRoutergoogle-vertex/europe	$5.5	$27.5	Source10/06/2026
	Google	Via OpenRoutergoogle-vertex/global	Lowest listed price: $5	Lowest listed price: $25	Source10/06/2026
	Google	Via OpenRoutergoogle-vertex/us	$5.5	$27.5	Source10/06/2026
DeepSeek-V4.1-Flash	DeepSeek	Direct from developerStandard API	$0.15	$0.6	Source09/23/2026
	Alibaba	Via OpenRouteralibaba	$0.15	$0.6	Source10/06/2026
	AtlasCloud	Via OpenRouteratlas-cloud/fp8	$0.141	$0.564	Source10/06/2026
	Baidu	Via OpenRouterbaidu/fp8	$0.3	$1.2	Source10/06/2026
	BaseTen	Via OpenRouterbaseten/fp8#1	$0.3	$1.2	Source10/06/2026
	BaseTen	Via OpenRouterbaseten/fp8#2	$0.3	$1.2	Source10/06/2026
	CoreWeave	Via OpenRoutercoreweave/fp8	$0.2	$0.65	Source10/06/2026
	Decart	Via OpenRouterdecart/fp4	$0.09	Lowest listed price: $0.18	Source10/06/2026
	DeepInfra	Via OpenRouterdeepinfra/fp8	$0.14	$0.42	Source10/06/2026
	DeepSeek	Via OpenRouterdeepseek	$0.15	$0.6	Source10/06/2026
	DekaLLM	Via OpenRouterdekallm	$0.12	$2.4	Source10/06/2026
	DigitalOcean	Via OpenRouterdigitalocean	$0.18	$0.72	Source10/06/2026
	Fireworks	Via OpenRouterfireworks/us	$0.45	$1.8	Source10/06/2026
	GMICloud	Via OpenRoutergmicloud/fp8	$0.18	$0.72	Source10/06/2026
	InferenceNet	Via OpenRouterinference-net	$0.07	$0.3	Source10/06/2026
	Ionstream	Via OpenRouterionstream	$0.1386	$1.175	Source10/06/2026
	Makora	Via OpenRoutermakora/fp8	$0.27	$1.15	Source10/06/2026
	Modal	Via OpenRoutermodal	$0.3	$1.2	Source10/06/2026
	Novita	Via OpenRouternovita/fp8	$0.195	$0.78	Source10/06/2026
	OpenInference	Via OpenRouteropen-inference/fp4	$0.055	$1.32	Source10/06/2026
	Parasail	Via OpenRouterparasail/fp8	$0.3	$1.2	Source10/06/2026
	Phala	Via OpenRouterphala	$0.21	$0.84	Source10/06/2026
	Reka	Via OpenRouterreka	$0.135	$1.08	Source10/06/2026
	Relace	Via OpenRouterrelace	Lowest listed price: $0.045	$1.2	Source10/06/2026
	Sail Research	Via OpenRoutersail-research/fp4	$0.08	$0.4	Source10/06/2026
	SiliconFlow	Via OpenRoutersiliconflow/fp8	$0.3	$1.2	Source10/06/2026
	StreamLake	Via OpenRouterstreamlake/fp8	$0.141	$0.564	Source10/06/2026
	Together	Via OpenRoutertogether	$0.3	$1.2	Source10/06/2026
	Venice	Via OpenRoutervenice/fp8	$0.3	$1.2	Source10/06/2026
	Wafer	Via OpenRouterwafer	$0.06	$1.2	Source10/06/2026

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.

Claude Opus 5

DeepSeek-V4.1-Flash

Coding: 100 / 61.2 (5 benchmark families)

Mathematics: 100 / 54.5 (1 benchmark family)

Finance: 100 / 84.1 (3 benchmark families)

Legal: 100 / 90.2 (3 benchmark families)

Agentic tasks: 93.3 / 94 (2 benchmark families)

Productivity: 100 / 83.6 (1 benchmark family)

Cybersecurity: 88.7 / 100 (1 benchmark family)

Health: 100 / 79.4 (2 benchmark families)

24 matched rows from 23 benchmark families were considered. The radar shows 8 of 11 comparable categories.

Claude Opus 5DeepSeek-V4.1-Flash

BioMysteryBenchOverall. Higher is better. No documented setup difference

Claude Opus 579.259 %

DeepSeek-V4.1-Flash67.778 %

Code MigrationOverall. Higher is better. No documented setup difference

Claude Opus 557.473 %

DeepSeek-V4.1-Flash45.623 %

CyberBench v1.1Overall. Higher is better. No documented setup difference

Claude Opus 565.357 %

DeepSeek-V4.1-Flash73.69 %

EMBOverall. Higher is better. No documented setup difference

Claude Opus 573.556 %

DeepSeek-V4.1-Flash57.208 %

Finance Agent (v2)Overall. Higher is better. No documented setup difference

Claude Opus 558.633 %

DeepSeek-V4.1-Flash53.481 %

Harvey's Legal Agent BenchmarkOverall · Task fully resolved. Higher is better. No documented setup difference

Claude Opus 56.667 %

DeepSeek-V4.1-Flash6.667 %

IOIOverall. Higher is better. No documented setup difference

Claude Opus 584.333 %

DeepSeek-V4.1-Flash40.278 %

Legal Research BenchOverall · All-pass. Higher is better. No documented setup difference

Claude Opus 555.288 %

DeepSeek-V4.1-Flash41.346 %

LegalBenchOverall. Higher is better. No documented setup difference

Claude Opus 586.974 %

DeepSeek-V4.1-Flash83.277 %

MedCodeOverall. Higher is better. No documented setup difference

Claude Opus 563.57 %

DeepSeek-V4.1-Flash41.173 %

MedScribeOverall. Higher is better. No documented setup difference

Claude Opus 590.985 %

DeepSeek-V4.1-Flash85.5 %

MysteryMechanismOverall. Higher is better. No documented setup difference

Claude Opus 537.387 %

DeepSeek-V4.1-Flash21.171 %

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for Claude Opus 5 and DeepSeek-V4.1-Flash
Benchmark and task	Claude Opus 5	DeepSeek-V4.1-Flash	Source
BioMysteryBenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is betterSettings: Harness: Terminus 2	Winner79.259 %	67.778 %	Vals AI Source details Data as of: 09/27/2026
Code MigrationOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner57.473 %	45.623 %	Vals AI Source details Data as of: 09/27/2026
CyberBench v1.1Overall Test details No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is better	65.357 %	Winner73.69 %	Vals AI Source details Data as of: 09/27/2026
EMBOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner73.556 %	57.208 %	Vals AI Source details Data as of: 09/27/2026
Finance Agent (v2)Overall Test details No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better	Winner58.633 %	53.481 %	Vals AI Source details Data as of: 09/27/2026
Harvey's Legal Agent BenchmarkOverall · Task fully resolved Test details No documented difference in the test setupVersion: 1Metric: task resolution rateScoring: Higher is better	Tie6.667 %	Tie6.667 %	Vals AI Source details Data as of: 09/27/2026
IOIOverall Test details No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better	Winner84.333 %	40.278 %	Vals AI Source details Data as of: 09/27/2026
Legal Research BenchOverall · All-pass Test details No documented difference in the test setupVersion: 1Metric: all-pass rateScoring: Higher is better	Winner55.288 %	41.346 %	Vals AI Source details Data as of: 09/27/2026
LegalBenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner86.974 %	83.277 %	Vals AI Source details Data as of: 09/27/2026
MedCodeOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner63.57 %	41.173 %	Vals AI Source details Data as of: 09/26/2026
MedScribeOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner90.985 %	85.5 %	Vals AI Source details Data as of: 09/26/2026
MysteryMechanismOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner37.387 %	21.171 %	Vals AI Source details Data as of: 09/27/2026
ProofBenchOverall Test details No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is better	Winner99 %	54 %	Vals AI Source details Data as of: 09/28/2026
Public Benefits Bench v1.1Overall Test details No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is better	Winner76.928 %	64.276 %	Vals AI Source details Data as of: 09/27/2026
SAGEOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner49.426 %	47.88 %	Vals AI Source details Data as of: 09/26/2026
SkillsBenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is betterSettings: Harness: OpenHands	60.441 %	Winner69.802 %	Vals AI Source details Data as of: 09/27/2026
SRE BenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner12.214 %	0.763 %	Vals AI Source details Data as of: 09/27/2026
Tax Agent BenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner75.06 %	62.458 %	Vals AI Source details Data as of: 09/27/2026
Terminal-Bench 2.1Overall Test details No documented difference in the test setupVersion: 2.1Metric: accuracyScoring: Higher is better	Winner84.644 %	74.532 %	Vals AI Source details Data as of: 09/27/2026
Terminal-Bench 4.0Overall Test details No documented difference in the test setupVersion: 4.0Metric: accuracyScoring: Higher is better	Winner45.455 %	11.616 %	Vals AI Source details Data as of: 09/27/2026
Terminal-Bench ScienceOverall Test details No documented difference in the test setupVersion: 0.1Metric: accuracyScoring: Higher is better	Winner22.857 %	4.286 %	Vals AI Source details Data as of: 09/27/2026
Vals IndexOverall Test details No documented difference in the test setupVersion: 2Metric: weighted index scoreScoring: Higher is better	Winner67.213 %	57.86 %	Vals AI Source details Data as of: 09/27/2026
Vibe Code Bench 1-100Overall Test details No documented difference in the test setupVersion: 1.0Metric: accuracyScoring: Higher is betterSettings: Harness: OpenHands	Winner28.533 %	16.378 %	Vals AI Source details Data as of: 09/22/2026
Vibe Code Bench v1.1Overall Test details No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is betterSettings: Harness: OpenHands	Winner88.404 %	84.739 %	Vals AI Source details Data as of: 09/27/2026
Key to the marks:better valuebetter, but not conclusivetie

Our model tests

Our tests

Compare how the models respond to the same prompt. Each test shows the latest attempt, with no subsequent fixes to the generated code. Earlier runs remain available in the test details. These results do not contribute to an overall score.

Pelican on a bicycle

A community classic for free-form SVG drawing.

Claude Opus 5

Reasoning (requested): high

Current attempt

Run date: 1 Oct 2026
API provider: openrouter
Requested API model: anthropic/claude-opus-5
API model reported in response: anthropic/claude-opus-5
Reasoning setting: high
Pinned endpoint: Anthropic | anthropic/claude-opus-5-20260723
Temperature: Provider default
Token limit including reasoning: 8,192 tokens
Test protocol: community-visual-tests-v1
Technical checks: Passed, not a quality rating
Response time: 63 s

Visually reviewed. This individual test does not establish overall model quality.

Earlier attempts (1)

7 Sept 2026API request failedReasoning setting: high

DeepSeek-V4.1-Flash

The response reached the token limit. No complete recording is available.

Reasoning (requested): high

Current attempt

Run date: 2 Oct 2026
API provider: openrouter
Requested API model: deepseek/deepseek-v4.1-flash
API model reported in response: deepseek/deepseek-v4.1-flash
Reasoning setting: high
Pinned endpoint: DeepSeek | deepseek/deepseek-v4.1-flash-20260910
Temperature: Provider default
Token limit including reasoning: 8,192 tokens
Test protocol: community-visual-tests-v1
Technical checks: Failed
Response time: 30.5 s

Not yet visually reviewed. A successful recording does not confirm correct physics or full compliance with the prompt.

Earlier attempts (1)

1 Oct 2026API request failedReasoning setting: high

Prompt and test conditions

Generate an SVG of a pelican riding a bicycle

Token limit including reasoning: 8,192 tokens

Task origin (Simon Willison)

How to read this comparison

Winning one benchmark is not an overall verdict

Your workload, budget, and required context length matter most. A coding benchmark says little about visual understanding or agent performance.

The standard price table uses direct developer rates. The provider comparison labels OpenRouter endpoints, regions, and special tariffs separately.

Every result links to its measurement source and retrieval date. Labels distinguish vendor reports, official benchmark leaderboards, and independent evaluations. Disputed or archived results are excluded.

More matchups

Compare Claude Opus 5 and DeepSeek-V4.1-Flash with other leading models using the same data and benchmark logic.

View the complete LLM comparison