Model comparison

Claude Sonnet 4 vs GPT-5.5 Pro

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 40.8 on the Noometry Index. Claude Sonnet 4 costs 11× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.

Last verified . 11 shared benchmarks.

Claude Sonnet 4 Anthropic

40.8

Rank #145 Confirmed

GPT-5.5 Pro OpenAI

64.3

Rank #8 Confirmed

Summary

  • They share 11 benchmarks with published results for both. Claude Sonnet 4 scores higher in 0 categories and GPT-5.5 Pro in 3 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.5 Pro leads 73.3 to 22.9.
  • The biggest single-benchmark swing is ARC-AGI-2: 5.9% for Claude Sonnet 4 and 84.6% for GPT-5.5 Pro.
  • Claude Sonnet 4 is cheaper at $3 / $15 per million input/output tokens, against $30 / $180 for GPT-5.5 Pro.
  • GPT-5.5 Pro accepts more context: 1.05M tokens versus 200K.

Side by side

Claude Sonnet 4 and GPT-5.5 Pro specifications
Claude Sonnet 4GPT-5.5 Pro
ProviderAnthropicOpenAI
Noometry Index40.864.3
Released2025-05-222026-04-23
WeightsProprietaryProprietary
Context window200K1.05M
Max output64K128K
Input $ / M tokens$3$30
Output $ / M tokens$15$180
Results tracked5814

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Category by category

Coding Not comparable

Claude Sonnet 4: 43.5 (#88), GPT-5.5 Pro: —

Coding benchmarks
BenchmarkClaude Sonnet 4GPT-5.5 Pro
SWE-bench Verified (bash only)64.9%—
Aider Polyglot61.3%—
SciCode40%—
GSO4.9%—
WeirdML46.1%—
LMArena Coding1414—
ALE-Bench655.35—

Agentic & Tool Use Not comparable

Claude Sonnet 4: 38.5 (#31), GPT-5.5 Pro: —

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 4GPT-5.5 Pro
TheAgentCompany33.1%—
Cybench35%—
DeepResearch Bench46.6%—
OSWorld43.9%—
METR Time Horizons62%—

Reasoning GPT-5.5 Pro leads

Claude Sonnet 4: 22.9 (#187), GPT-5.5 Pro: 73.3 (#10)

Reasoning benchmarks
BenchmarkClaude Sonnet 4GPT-5.5 Pro
ARC-AGI-25.9%84.6%
SimpleBench45.5%76.9%
ARC-AGI-140%96.5%
CritPt0.3%30.6%
DTBench77.1%96%
LMCA29%53.9%
Epoch Capabilities Index141.69162.07
Kagi LLM Benchmark73%—
Chess Puzzles—64%
EnigmaEval3.1%—
LMArena Hard Prompts1372—
ForecastBench60.2—

Math GPT-5.5 Pro leads

Claude Sonnet 4: 43.3 (#80), GPT-5.5 Pro: 84.0 (#10)

Math benchmarks
BenchmarkClaude Sonnet 4GPT-5.5 Pro
OTIS Mock AIME 2024-202571.1%100%
FrontierMath (Feb 2025 set)4.1%52.4%
FrontierMath Tier 4 (v1)0%39.6%
FrontierMath (Tiers 1-3)—87.7%
FrontierMath Tier 4—78%
Omni-MATH60.2%—
LMArena Math1375—
MATH Level 584.4%—

Knowledge GPT-5.5 Pro leads

Claude Sonnet 4: 41.8 (#108), GPT-5.5 Pro: 64.1 (#19)

Knowledge benchmarks
BenchmarkClaude Sonnet 4GPT-5.5 Pro
GPQA Diamond79.2%93.9%
Humanity's Last Exam7.8%—
MMLU-Pro84.3%—
Confabulations13.2%—
Vectara Hallucination Rate10.3%—
GPQA (HELM)70.6%—
LMArena Expert1372—

Multimodal Not comparable

Claude Sonnet 4: 26.2 (#121), GPT-5.5 Pro: —

Multimodal benchmarks
BenchmarkClaude Sonnet 4GPT-5.5 Pro
LMArena Vision1191—
GeoBench37%—
VPCT34%—
MindCube44.8%—

Multilingual Not comparable

Claude Sonnet 4: 46.7 (#156), GPT-5.5 Pro: —

Multilingual benchmarks
BenchmarkClaude Sonnet 4GPT-5.5 Pro
LMArena Non-English1333—
LMArena Chinese1350—
LMArena French1363—
LMArena German1331—
LMArena Japanese1302—
LMArena Korean1291—
LMArena Russian1355—
LMArena Spanish1357—

Instruction Following Not comparable

Claude Sonnet 4: 71.7 (#145), GPT-5.5 Pro: —

Instruction Following benchmarks
BenchmarkClaude Sonnet 4GPT-5.5 Pro
IFEval84%—
LMArena Instruction Following1376—

Long Context Not comparable

Claude Sonnet 4: 33.7 (#259), GPT-5.5 Pro: —

Long Context benchmarks
BenchmarkClaude Sonnet 4GPT-5.5 Pro
Fiction.LiveBench46.9%—
LMArena Longer Query1398—

Writing & Preference Not comparable

Claude Sonnet 4: 57.1 (#132), GPT-5.5 Pro: —

Writing & Preference benchmarks
BenchmarkClaude Sonnet 4GPT-5.5 Pro
LMArena Text1351—
LMArena Creative Writing1345—
Short-Story Creative Writing81.4%—
EQ-Bench Creative Writing1483—
WildBench83.8%—
LMArena Multi-Turn1376—

Frequently asked questions

Is Claude Sonnet 4 better than GPT-5.5 Pro?

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 40.8 on the Noometry Index. Claude Sonnet 4 costs 11× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 4 or GPT-5.5 Pro?

Claude Sonnet 4 is cheaper. It lists at $3 per million input tokens and $15 per million output tokens; GPT-5.5 Pro lists at $30 and $180.

Which has the bigger context window?

GPT-5.5 Pro does, with 1.05M tokens against 200K.

How many benchmarks do Claude Sonnet 4 and GPT-5.5 Pro share?

11 benchmarks have published results for both models. Claude Sonnet 4 has 58 scored results on Noometry and GPT-5.5 Pro has 14.

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