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Head-to-head comparison

Claude Sonnet 4.5 vs. GPT-5.6 Sol

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

shared result series
2
distinct benchmarks
2
latest retrieval
2026-08-26

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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 4.5 and GPT-5.6 Sol
AttributeClaude Sonnet 4.5GPT-5.6 Sol
ProviderAnthropicOpenAI
ReleasedSep 2025Jul 9, 2026
AvailabilityActiveActive
Model typeProprietaryProprietary
ParametersNot publishedNot published
ArchitectureNot publishedNot published
Context window200,000 tokens1,050,000 tokens
Knowledge cutoffJanuary 2025February 16, 2026
Technical sourcesModel, ContextModel, Context, Knowledge cutoff

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 4.5 and GPT-5.6 Sol
Price typeClaude Sonnet 4.5GPT-5.6 Sol
API input$3$4 ≤272K / $8 >272K
API output$15$20 ≤272K / $30 >272K
Cache read$0.3$0.4 ≤272K / $0.8 >272K
Cache write (5 min.)$3.75$5 ≤272K / $10 >272K
Cache write (1 hr.)$6Not listed
Price verified07/30/2026 Source08/24/2026 Source
Claude Sonnet 4.5GPT-5.6 Sol
API inputUSD per 1M tokens, base tier
Claude Sonnet 4.5Lower price$3
GPT-5.6 Sol$4
API outputUSD per 1M tokens, base tier
Claude Sonnet 4.5Lower price$15
GPT-5.6 Sol$20
Cache readUSD per 1M tokens, base tier
Claude Sonnet 4.5Lower price$0.3
GPT-5.6 Sol$0.4

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 4.5 and GPT-5.6 Sol
ModelProviderPurchase route and tariffInput per 1M tokensOutput per 1M tokensSource
Claude Sonnet 4.5AnthropicDirect from developerStandard APILowest listed price: $3Lowest listed price: $15Source07/30/2026
Amazon BedrockVia OpenRouteramazon-bedrockLowest listed price: $3Lowest listed price: $15Source09/12/2026
Amazon BedrockVia OpenRouteramazon-bedrock/eu-west-1$3.3$16.5Source09/12/2026
AnthropicVia OpenRouteranthropicLowest listed price: $3Lowest listed price: $15Source09/12/2026
AzureVia OpenRouterazure/globalLowest listed price: $3Lowest listed price: $15Source09/12/2026
Claude Platform on AWSVia OpenRouterclaude-on-awsLowest listed price: $3Lowest listed price: $15Source09/12/2026
GoogleVia OpenRoutergoogle-vertex/globalLowest listed price: $3Lowest listed price: $15Source09/12/2026
GoogleVia OpenRoutergoogle-vertex/us-east5$3.3$16.5Source09/12/2026
GPT-5.6 SolOpenAIDirect from developerUp to 272,000 context tokens$4$20Source08/24/2026
OpenAIDirect from developerAbove 272,000 context tokens$8$30Source08/24/2026
Amazon BedrockVia OpenRouteramazon-bedrock/us-east-1$4.4$22Source09/12/2026
AzureVia OpenRouterazure$5$30Source09/12/2026
AzureVia OpenRouterazure/eu$5.5$33Source09/12/2026
AzureVia OpenRouterazure/us$5.5$33Source09/12/2026
OpenAIVia OpenRouteropenai$2$10Source09/12/2026
OpenAIVia OpenRouteropenai/fast$4$20Source09/12/2026
OpenAIVia OpenRouteropenai/flexLowest listed price: $1Lowest listed price: $5Source09/12/2026

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.

Not enough directly matched categories for a reliable radar

Only 0 of at least 5 categories have comparable, direct model measurements. The benchmark tables below show the available evidence without filling missing axes.

Claude Sonnet 4.5GPT-5.6 Sol
PRBench FinanceOverall. Higher is better. Test setup not documented as identical
Claude Sonnet 4.543.79% ± 0.4
GPT-5.6 SolHigher measured value50.45% ± 0.33
PRBench LegalOverall. Higher is better. Test setup not documented as identical
Claude Sonnet 4.540.84% ± 0.4
GPT-5.6 SolHigher measured value50.5% ± 0.54

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for Claude Sonnet 4.5 and GPT-5.6 Sol
Benchmark and taskClaude Sonnet 4.5GPT-5.6 SolSource
PRBench FinanceOverall
Test details
Test setup not documented as identicalNo direct winnerVersion: full finance setMetric: weighted rubric scoreScoring: Higher is betterClaude Sonnet 4.5: Attempts: pass@1
GPT-5.6 Sol: Snapshot: gpt-5.6-sol-max, Reasoning: max, Attempts: pass@1
600 finance tasks with task-specific rubrics and o4-mini as judge.
43.79% ± 0.4
95% confidence interval: ±0.4
Higher measured value50.45% ± 0.33
95% confidence interval: ±0.33
Scale AI
Source details
Data as of: 08/26/2026
PRBench LegalOverall
Test details
Test setup not documented as identicalNo direct winnerVersion: full legal setMetric: weighted rubric scoreScoring: Higher is betterClaude Sonnet 4.5: Attempts: pass@1
GPT-5.6 Sol: Snapshot: gpt-5.6-sol-max, Reasoning: max, Attempts: pass@1
500 legal tasks with task-specific rubrics and o4-mini as judge.
40.84% ± 0.4
95% confidence interval: ±0.4
Higher measured value50.5% ± 0.54
95% confidence interval: ±0.54
Scale AI
Source details
Data as of: 08/26/2026

Key to the marks:better valuebetter, but not conclusivetie

Our model tests

Community tests you can inspect

Compare how the models respond to the same prompt. Each test shows the first attempt, with no subsequent fixes to the generated code. These results do not contribute to an overall score.

Pelican on a bicycle

A community classic for free-form SVG drawing.

Claude Sonnet 4.5

Not tested yet

GPT-5.6 Sol

API access was unavailable for this run. The model was not evaluated.

First attempt
Run date
7 Sept 2026
API provider
openrouter
Requested API model
openai/gpt-5.6-sol
Pinned endpoint
OpenAI | openai/gpt-5.6-sol-20260709
Reasoning setting
high
Temperature
Provider default
Token limit including reasoning
8,192 tokens
Test protocol
community-visual-tests-v1
Technical checks
Not run

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

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 Sonnet 4.5 and GPT-5.6 Sol with other leading models using the same data and benchmark logic.

View the complete LLM comparison