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Head-to-head comparison

Claude Opus 4.8 vs. Claude Sonnet 4.6

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

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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 Opus 4.8 and Claude Sonnet 4.6
AttributeClaude Opus 4.8Claude Sonnet 4.6
ProviderAnthropicAnthropic
ReleasedMay 2026Feb 2026
AvailabilityLegacyActive
Model typeProprietaryProprietary
ParametersNot publishedNot published
ArchitectureNot publishedNot published
Context window1,000,000 tokens1,000,000 tokens
Knowledge cutoffJanuary 2026August 2025
Technical sourcesModel, Knowledge cutoffModel, Context

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 4.8 and Claude Sonnet 4.6
Price typeClaude Opus 4.8Claude Sonnet 4.6
API input$5$3
API output$25$15
Cache read$0.5$0.3
Cache write (5 min.)$6.25$3.75
Cache write (1 hr.)$10$6
Price verified09/22/2026 Source09/22/2026 Source
Claude Opus 4.8Claude Sonnet 4.6
API inputUSD per 1M tokens, base tier
Claude Opus 4.8$5
Claude Sonnet 4.6Lower price$3
API outputUSD per 1M tokens, base tier
Claude Opus 4.8$25
Claude Sonnet 4.6Lower price$15
Cache readUSD per 1M tokens, base tier
Claude Opus 4.8$0.5
Claude Sonnet 4.6Lower price$0.3

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.

No provider tariff for Claude Opus 4.8 is available in the stored OpenRouter snapshot. The official direct price is still shown.

Provider pricing for Claude Opus 4.8 and Claude Sonnet 4.6
ModelProviderPurchase route and tariffInput per 1M tokensOutput per 1M tokensSource
Claude Opus 4.8AnthropicDirect from developerStandard APILowest listed price: $5Lowest listed price: $25Source09/22/2026
Claude Sonnet 4.6AnthropicDirect from developerStandard APILowest listed price: $3Lowest listed price: $15Source09/22/2026
Amazon BedrockVia OpenRouteramazon-bedrock/eu-west-1$3.3$16.5Source10/05/2026
Amazon BedrockVia OpenRouteramazon-bedrock/globalLowest listed price: $3Lowest listed price: $15Source10/05/2026
Amazon BedrockVia OpenRouteramazon-bedrock/us$3.3$16.5Source10/05/2026
AnthropicVia OpenRouteranthropicLowest listed price: $3Lowest listed price: $15Source10/05/2026
AzureVia OpenRouterazure/globalLowest listed price: $3Lowest listed price: $15Source10/05/2026
Claude Platform on AWSVia OpenRouterclaude-on-awsLowest listed price: $3Lowest listed price: $15Source10/05/2026
GoogleVia OpenRoutergoogle-vertex/europe$3.3$16.5Source10/05/2026
GoogleVia OpenRoutergoogle-vertex/globalLowest listed price: $3Lowest listed price: $15Source10/05/2026
GoogleVia OpenRoutergoogle-vertex/us-east5$3.3$16.5Source10/05/2026

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.

255075100CodingReasoningKnowledgeFinanceLegalAgentic tasksMultimodalProductivity
Claude Opus 4.8
Claude Sonnet 4.6
Coding: 100 / 75.5 (5 benchmark families)
Reasoning: 100 / 92.6 (1 benchmark family)
Knowledge: 100 / 97.5 (1 benchmark family)
Finance: 99.7 / 96 (6 benchmark families)
Legal: 100 / 79.5 (3 benchmark families)
Agentic tasks: 100 / 82.6 (2 benchmark families)
Multimodal: 100 / 96.5 (1 benchmark family)
Productivity: 100 / 91.7 (1 benchmark family)

24 matched rows from 23 benchmark families were considered. The radar shows 8 of 10 comparable categories.

Claude Opus 4.8Claude Sonnet 4.6
Code MigrationOverall. Higher is better. No documented setup difference
Claude Opus 4.8Winner47.25 %
Claude Sonnet 4.639.892 %
CorpFin v2Overall. Higher is better. No documented setup difference
Claude Opus 4.8Winner66.706 %
Claude Sonnet 4.665.307 %
EMBOverall. Higher is better. No documented setup difference
Claude Opus 4.8Winner69.373 %
Claude Sonnet 4.660.154 %
Finance Agent (v2)Overall. Higher is better. No documented setup difference
Claude Opus 4.8Winner53.918 %
Claude Sonnet 4.651.035 %
GPQA DiamondOverall. Higher is better. No documented setup difference
Claude Opus 4.8Winner92.424 %
Claude Sonnet 4.685.606 %
Harvey's Legal Agent BenchmarkOverall · Task fully resolved. Higher is better. No documented setup difference
Claude Opus 4.8Winner9.583 %
Claude Sonnet 4.65 %
Legal Research BenchOverall · All-pass. Higher is better. No documented setup difference
Claude Opus 4.8Winner43.75 %
Claude Sonnet 4.638.462 %
LegalBenchOverall. Higher is better. No documented setup difference
Claude Opus 4.8Winner83.568 %
Claude Sonnet 4.682.12 %
LiveCodeBench v6Overall. Higher is better. No documented setup difference
Claude Opus 4.8Winner87.819 %
Claude Sonnet 4.682.091 %
MMLU-ProOverall. Higher is better. No documented setup difference
Claude Opus 4.8Winner89.585 %
Claude Sonnet 4.687.341 %
MMMU-ProOverall. Higher is better. No documented setup difference
Claude Opus 4.8Winner86.59 %
Claude Sonnet 4.683.584 %
MortgageTaxOverall. Higher is better. No documented setup difference
Claude Opus 4.8Winner69.912 %
Claude Sonnet 4.667.726 %

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for Claude Opus 4.8 and Claude Sonnet 4.6
Benchmark and taskClaude Opus 4.8Claude Sonnet 4.6Source
Code MigrationOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner47.25 %
39.892 %
Vals AI
Source details
Data as of: 09/27/2026
CorpFin v2Overall
Test details
No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better
Winner66.706 %
65.307 %
Vals AI
Source details
Data as of: 08/12/2026
EMBOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner69.373 %
60.154 %
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
Winner53.918 %
51.035 %
Vals AI
Source details
Data as of: 09/27/2026
GPQA DiamondOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner92.424 %
85.606 %
Vals AI
Source details
Data as of: 09/01/2026
Harvey's Legal Agent BenchmarkOverall · Task fully resolved
Test details
No documented difference in the test setupVersion: 1Metric: task resolution rateScoring: Higher is better
Winner9.583 %
5 %
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
Winner43.75 %
38.462 %
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
Winner83.568 %
82.12 %
Vals AI
Source details
Data as of: 09/27/2026
LiveCodeBench v6Overall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner87.819 %
82.091 %
Vals AI
Source details
Data as of: 09/01/2026
MMLU-ProOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner89.585 %
87.341 %
Vals AI
Source details
Data as of: 09/01/2026
MMMU-ProOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner86.59 %
83.584 %
Vals AI
Source details
Data as of: 09/01/2026
MortgageTaxOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner69.912 %
67.726 %
Vals AI
Source details
Data as of: 09/01/2026
ProgramBenchOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner1 %
0.5 %
Vals AI
Source details
Data as of: 09/27/2026
Public Benefits Bench v1.1Overall
Test details
No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is better
Winner68.133 %
62.449 %
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
Winner54.788 %
46.582 %
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
Winner59.227 %
49.052 %
Vals AI
Source details
Data as of: 09/27/2026
SWE-bench VerifiedOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner88.6 %
77.4 %
Vals AI
Source details
Data as of: 09/01/2026
Tax Agent BenchOverall
Test details
No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better
Winner64.906 %
64.854 %
Vals AI
Source details
Data as of: 09/27/2026
TaxEval v2Overall
Test details
No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better
75.634 %
Winner77.106 %
Vals AI
Source details
Data as of: 09/01/2026
Terminal-Bench 2.0Overall
Test details
No documented difference in the test setupVersion: 2.0Metric: accuracyScoring: Higher is better
Winner70.037 %
59.551 %
Vals AI
Source details
Data as of: 06/04/2026
Terminal-Bench 2.1Overall
Test details
No documented difference in the test setupVersion: 2.1Metric: accuracyScoring: Higher is better
Winner71.91 %
57.303 %
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
Winner60.908 %
50.593 %
Vals AI
Source details
Data as of: 09/27/2026
Vals Multimodal IndexOverall
Test details
No documented difference in the test setupVersion: 1.2Metric: weighted index scoreScoring: Higher is better
Winner70.889 %
60.571 %
Vals AI
Source details
Data as of: 08/11/2026
Vibe Code Bench v1.1Overall
Test details
No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is betterSettings: Harness: OpenHands
Winner82.725 %
51.476 %
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 4.8

Claude Opus 4.8: Pelican on a bicycle
A community classic for free-form SVG drawing.

Reasoning (requested): high

Current attempt
Run date
1 Oct 2026
API provider
openrouter
Requested API model
anthropic/claude-opus-4.8
API model reported in response
anthropic/claude-opus-4.8
Reasoning setting
high
Pinned endpoint
Anthropic | anthropic/claude-4.8-opus-20260528
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
18 s

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

Claude Sonnet 4.6

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
anthropic/claude-sonnet-4.6
API model reported in response
anthropic/claude-sonnet-4.6
Reasoning setting
high
Pinned endpoint
Anthropic | anthropic/claude-4.6-sonnet-20260217
Temperature
Provider default
Token limit including reasoning
8,192 tokens
Test protocol
community-visual-tests-v1
Technical checks
Failed
Response time
110 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

Related LLM comparisons

Compare Claude Opus 4.8 and Claude Sonnet 4.6 with other leading models using the same data and benchmark logic.

View the complete LLM comparison