Model comparison
Claude Sonnet 5.5 vs GPT-5 Pro
Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 46.2 on the Noometry Index.
Last verified . 2 shared benchmarks.
Summary
- They share 2 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 4 categories and GPT-5 Pro in 0 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 5.5 leads 88.7 to 48.0.
- The biggest single-benchmark swing is FrontierMath Tier 4: 80.5% for Claude Sonnet 5.5 and 19.5% for GPT-5 Pro.
- Claude Sonnet 5.5 is cheaper at $2 / $10 per million input/output tokens, against $15 / $120 for GPT-5 Pro.
- Claude Sonnet 5.5 accepts more context: 1M tokens versus 400K.
Side by side
| Claude Sonnet 5.5 | GPT-5 Pro | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 60.5 | 46.2 |
| Released | 2026-09-28 | 2025-10-06 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 400K |
| Max output | 128K | 272K |
| Input $ / M tokens | $2 | $15 |
| Output $ / M tokens | $10 | $120 |
| Results tracked | 16 | 12 |
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Category by category
Coding Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 65.5 (#6), GPT-5 Pro: 43.4 (#77)
| Benchmark | Claude Sonnet 5.5 | GPT-5 Pro |
|---|---|---|
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| LMArena WebDev | 1699 | — |
| FrontierSWE | 61.9% | — |
| SciCode | 61% | — |
| WeirdML | — | 60.4% |
| ALE-Bench | 1,819 | — |
| AlgoTune | — | 1.31 |
Agentic & Tool Use Not comparable
Claude Sonnet 5.5: 44.9 (#14), GPT-5 Pro: —
| Benchmark | Claude Sonnet 5.5 | GPT-5 Pro |
|---|---|---|
| APEX-Agents | 75.5% | — |
Reasoning Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 52.4 (#29), GPT-5 Pro: 39.2 (#52)
| Benchmark | Claude Sonnet 5.5 | GPT-5 Pro |
|---|---|---|
| ARC-AGI-2 | — | 18.3% |
| SimpleBench | — | 61.6% |
| Kagi LLM Benchmark | — | 76.8% |
| ARC-AGI-1 | — | 70.2% |
| CritPt | 31.4% | — |
| EnigmaEval | — | 18.8% |
| Mystery Game Puzzles | 65% | — |
| Epoch Capabilities Index | — | 150.26 |
Math Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 88.7 (#4), GPT-5 Pro: 48.0 (#53)
| Benchmark | Claude Sonnet 5.5 | GPT-5 Pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | 88.8% | 55.8% |
| FrontierMath Tier 4 | 80.5% | 19.5% |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 100% | — |
| FrontierMath Tier 4 (v1) | — | 14.6% |
Knowledge Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#11), GPT-5 Pro: 56.2 (#39)
| Benchmark | Claude Sonnet 5.5 | GPT-5 Pro |
|---|---|---|
| GPQA Diamond | 95.6% | — |
| Humanity's Last Exam | — | 31.6% |
| SimpleQA Verified | 46.5% | — |
Multimodal Not comparable
Claude Sonnet 5.5: 53.2 (#5), GPT-5 Pro: —
| Benchmark | Claude Sonnet 5.5 | GPT-5 Pro |
|---|---|---|
| Furniture Assembly | 75% | — |
Frequently asked questions
Is Claude Sonnet 5.5 better than GPT-5 Pro?
Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 46.2 on the Noometry Index.
Which is cheaper, Claude Sonnet 5.5 or GPT-5 Pro?
Claude Sonnet 5.5 is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; GPT-5 Pro lists at $15 and $120.
Is Claude Sonnet 5.5 or GPT-5 Pro better for coding?
Claude Sonnet 5.5 scores higher on coding benchmarks: 65.5 versus 43.4 in the Noometry coding category.
Which has the bigger context window?
Claude Sonnet 5.5 does, with 1M tokens against 400K.
How many benchmarks do Claude Sonnet 5.5 and GPT-5 Pro share?
2 benchmarks have published results for both models. Claude Sonnet 5.5 has 16 scored results on Noometry and GPT-5 Pro has 12.