Model comparison
Claude Sonnet 5.5 vs GPT-6 Sol
Claude Sonnet 5.5 and GPT-6 Sol score almost the same on the Noometry Index (61.9 vs 61.8), so choose on price, context window or the category you care about most.
Last verified . 29 shared benchmarks.
Summary
- They share 29 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 8 categories and GPT-6 Sol in 2 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-6 Sol leads 74.0 to 54.0.
- The biggest single-benchmark swing is APEX-Agents: 75.5% for Claude Sonnet 5.5 and 54.3% for GPT-6 Sol.
- Both cost about the same: $2 input and $10 output per million tokens.
- GPT-6 Sol accepts more context: 1.05M tokens versus 1M.
Side by side
| Claude Sonnet 5.5 | GPT-6 Sol | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 61.9 | 61.8 |
| Released | 2026-09-28 | 2026-09-22 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 1.05M |
| Max output | 128K | 128K |
| Input $ / M tokens | $2 | $2 |
| Output $ / M tokens | $10 | $10 |
| Results tracked | 32 | 45 |
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Category by category
Coding Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 67.3 (#6), GPT-6 Sol: 60.1 (#11)
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| FrontierCode | 52.1% | 49.3% |
| LMArena WebDev | 1774 | 1688 |
| SciCode | 61% | 57.6% |
| LMArena Coding | 1513 | 1447 |
| ALE-Bench | 1,819 | 2,462 |
| DeepSWE | — | 68.8% |
| CursorBench | 55.5% | — |
| FrontierSWE | 61.9% | — |
Agentic & Tool Use Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 45.0 (#16), GPT-6 Sol: 37.2 (#36)
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| APEX-Agents | 75.5% | 54.3% |
| GDP.pdf | — | 26.4% |
| Vending-Bench 2 | — | 14,428 |
Reasoning GPT-6 Sol leads
Claude Sonnet 5.5: 54.0 (#28), GPT-6 Sol: 74.0 (#9)
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| NYT Connections (extended) | 80.5% | 90.1% |
| CritPt | 31.4% | 30.9% |
| LMArena Hard Prompts | 1495 | 1418 |
| Mystery Game Puzzles | 65% | 56% |
| Epoch Capabilities Index | 165.03 | 162.72 |
| ARC-AGI-2 | — | 89.6% |
| ARC-AGI-1 | — | 95.5% |
| EBR-Bench | — | 53.3% |
| DTBench | — | 97.3% |
| LMCA | — | 59.1% |
Math Too close to call
Claude Sonnet 5.5: 87.9 (#6), GPT-6 Sol: 87.2 (#7)
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| FrontierMath (Tiers 1-3) | 88.8% | 89.8% |
| FrontierMath Tier 4 | 80.5% | 90% |
| OTIS Mock AIME 2024-2025 | 100% | 100% |
| ProofBench | 100% | 83% |
| LMArena Math | 1510 | 1402 |
| FrontierMath Erdős | 2.9% | — |
Knowledge Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#12), GPT-6 Sol: 64.8 (#15)
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| GPQA Diamond | 95.6% | 94.3% |
| SimpleQA Verified | 46.5% | 60.7% |
| LMArena Expert | 1540 | 1439 |
| Vectara Hallucination Rate | — | 6.5% |
Multimodal Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 51.5 (#6), GPT-6 Sol: 47.6 (#10)
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| LMArena Vision | 1289 | 1245 |
| Furniture Assembly | 75% | 58.3% |
| Blueprint-Bench 2 | — | 36.9% |
Multilingual Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 55.3 (#30), GPT-6 Sol: 50.5 (#118)
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| LMArena Non-English | 1452 | 1385 |
| LMArena Chinese | 1522 | 1405 |
| LMArena Russian | 1451 | 1401 |
| LMArena French | — | 1410 |
| LMArena German | — | 1390 |
| LMArena Japanese | — | 1385 |
| LMArena Korean | — | 1341 |
| LMArena Spanish | — | 1384 |
Instruction Following Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 78.3 (#11), GPT-6 Sol: 74.5 (#94)
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| LMArena Instruction Following | 1495 | 1412 |
Long Context Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 45.9 (#28), GPT-6 Sol: 43.1 (#108)
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| LMArena Longer Query | 1498 | 1411 |
Writing & Preference GPT-6 Sol leads
Claude Sonnet 5.5: 66.0 (#40), GPT-6 Sol: 71.9 (#18)
| Benchmark | Claude Sonnet 5.5 | GPT-6 Sol |
|---|---|---|
| LMArena Text | 1471 | 1395 |
| LMArena Creative Writing | 1465 | 1378 |
| LMArena Multi-Turn | 1474 | 1412 |
| EQ-Bench Creative Writing | — | 2125 |
Frequently asked questions
Is Claude Sonnet 5.5 better than GPT-6 Sol?
Claude Sonnet 5.5 and GPT-6 Sol score almost the same on the Noometry Index (61.9 vs 61.8), so choose on price, context window or the category you care about most.
Which is cheaper, Claude Sonnet 5.5 or GPT-6 Sol?
GPT-6 Sol is cheaper. It lists at $2 per million input tokens and $10 per million output tokens; Claude Sonnet 5.5 lists at $2 and $10.
Is Claude Sonnet 5.5 or GPT-6 Sol better for coding?
Claude Sonnet 5.5 scores higher on coding benchmarks: 67.3 versus 60.1 in the Noometry coding category.
Which has the bigger context window?
GPT-6 Sol does, with 1.05M tokens against 1M.
How many benchmarks do Claude Sonnet 5.5 and GPT-6 Sol share?
29 benchmarks have published results for both models. Claude Sonnet 5.5 has 32 scored results on Noometry and GPT-6 Sol has 45.