Model comparison
Claude Sonnet 4 vs GPT-5.5 Pro
GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 40.6 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.
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 73.6 to 23.0.
- 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 | GPT-5.5 Pro | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 40.6 | 64.3 |
| Released | 2025-05-22 | 2026-04-23 |
| Weights | Proprietary | Proprietary |
| Context window | 200K | 1.05M |
| Max output | 64K | 128K |
| Input $ / M tokens | $3 | $30 |
| Output $ / M tokens | $15 | $180 |
| Results tracked | 58 | 14 |
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Category by category
Coding Not comparable
Claude Sonnet 4: 44.0 (#70), GPT-5.5 Pro: —
| Benchmark | Claude Sonnet 4 | GPT-5.5 Pro |
|---|---|---|
| SWE-bench Verified (bash only) | 64.9% | — |
| Aider Polyglot | 61.3% | — |
| SciCode | 40% | — |
| GSO | 4.9% | — |
| WeirdML | 46.1% | — |
| LMArena Coding | 1414 | — |
| ALE-Bench | 655.35 | — |
Agentic & Tool Use Not comparable
Claude Sonnet 4: 38.3 (#29), GPT-5.5 Pro: —
| Benchmark | Claude Sonnet 4 | GPT-5.5 Pro |
|---|---|---|
| TheAgentCompany | 33.1% | — |
| Cybench | 35% | — |
| DeepResearch Bench | 46.6% | — |
| OSWorld | 43.9% | — |
| METR Time Horizons | 62% | — |
Reasoning GPT-5.5 Pro leads
Claude Sonnet 4: 23.0 (#169), GPT-5.5 Pro: 73.6 (#7)
| Benchmark | Claude Sonnet 4 | GPT-5.5 Pro |
|---|---|---|
| ARC-AGI-2 | 5.9% | 84.6% |
| SimpleBench | 45.5% | 76.9% |
| ARC-AGI-1 | 40% | 96.5% |
| CritPt | 0.3% | 30.6% |
| DTBench | 77.1% | 96% |
| LMCA | 29% | 53.9% |
| Epoch Capabilities Index | 141.69 | 162.45 |
| Kagi LLM Benchmark | 73% | — |
| Chess Puzzles | — | 64% |
| EnigmaEval | 3.1% | — |
| LMArena Hard Prompts | 1372 | — |
| ForecastBench | 60.2 | — |
Math GPT-5.5 Pro leads
Claude Sonnet 4: 41.5 (#71), GPT-5.5 Pro: 83.8 (#8)
| Benchmark | Claude Sonnet 4 | GPT-5.5 Pro |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 71.1% | 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-MATH | 60.2% | — |
| LMArena Math | 1375 | — |
| MATH Level 5 | 84.4% | — |
Knowledge GPT-5.5 Pro leads
Claude Sonnet 4: 41.6 (#99), GPT-5.5 Pro: 64.2 (#17)
| Benchmark | Claude Sonnet 4 | GPT-5.5 Pro |
|---|---|---|
| GPQA Diamond | 79.2% | 93.9% |
| Humanity's Last Exam | 7.8% | — |
| MMLU-Pro | 84.3% | — |
| Confabulations | 13.2% | — |
| Vectara Hallucination Rate | 10.3% | — |
| GPQA (HELM) | 70.6% | — |
| LMArena Expert | 1371 | — |
Multimodal Not comparable
Claude Sonnet 4: 25.6 (#116), GPT-5.5 Pro: —
| Benchmark | Claude Sonnet 4 | GPT-5.5 Pro |
|---|---|---|
| LMArena Vision | 1191 | — |
| GeoBench | 37% | — |
| VPCT | 34% | — |
| MindCube | 44.8% | — |
Multilingual Not comparable
Claude Sonnet 4: 46.9 (#151), GPT-5.5 Pro: —
| Benchmark | Claude Sonnet 4 | GPT-5.5 Pro |
|---|---|---|
| LMArena Non-English | 1333 | — |
| LMArena Chinese | 1351 | — |
| LMArena French | 1364 | — |
| LMArena German | 1331 | — |
| LMArena Japanese | 1301 | — |
| LMArena Korean | 1293 | — |
| LMArena Russian | 1355 | — |
| LMArena Spanish | 1356 | — |
Instruction Following Not comparable
Claude Sonnet 4: 71.8 (#141), GPT-5.5 Pro: —
| Benchmark | Claude Sonnet 4 | GPT-5.5 Pro |
|---|---|---|
| IFEval | 84% | — |
| LMArena Instruction Following | 1375 | — |
Long Context Not comparable
Claude Sonnet 4: 33.6 (#254), GPT-5.5 Pro: —
| Benchmark | Claude Sonnet 4 | GPT-5.5 Pro |
|---|---|---|
| Fiction.LiveBench | 46.9% | — |
| LMArena Longer Query | 1398 | — |
Writing & Preference Not comparable
Claude Sonnet 4: 57.3 (#127), GPT-5.5 Pro: —
| Benchmark | Claude Sonnet 4 | GPT-5.5 Pro |
|---|---|---|
| LMArena Text | 1351 | — |
| LMArena Creative Writing | 1345 | — |
| Short-Story Creative Writing | 81.4% | — |
| EQ-Bench Creative Writing | 1483 | — |
| WildBench | 83.8% | — |
| LMArena Multi-Turn | 1376 | — |
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 40.6 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.