Model comparison
Claude Opus 4.6 vs GPT-5.5 Instant
Claude Opus 4.6 is the stronger model overall, scoring 58.2 to 42.7 on the Noometry Index.
Last verified . 25 shared benchmarks.
Summary
- They share 25 benchmarks with published results for both. Claude Opus 4.6 scores higher in 8 categories and GPT-5.5 Instant in 1 category; 9 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Opus 4.6 leads 63.0 to 26.5.
- The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 66% for Claude Opus 4.6 and 26.3% for GPT-5.5 Instant.
Side by side
| Claude Opus 4.6 | GPT-5.5 Instant | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 58.2 | 42.7 |
| Released | 2026-02-04 | 2026-05-05 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | — |
| Max output | 128K | — |
| Input $ / M tokens | $5 | — |
| Output $ / M tokens | $25 | — |
| Results tracked | 68 | 27 |
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Category by category
Coding Claude Opus 4.6 leads
Claude Opus 4.6: 57.2 (#20), GPT-5.5 Instant: 44.3 (#74)
| Benchmark | Claude Opus 4.6 | GPT-5.5 Instant |
|---|---|---|
| LMArena Coding | 1536 | 1433 |
| SWE-bench Verified | 78.7% | — |
| FrontierCode | 26.6% | — |
| SWE-bench Verified (bash only) | 75.6% | — |
| LMArena WebDev | 1547 | — |
| SWE-bench Multilingual | 72% | — |
| SciCode | — | 48.6% |
| GSO | 41.2% | — |
| WeirdML | 78% | — |
| ALE-Bench | 996.5 | — |
| AlgoTune | 1.47 | — |
Agentic & Tool Use Not comparable
Claude Opus 4.6: 51.1 (#4), GPT-5.5 Instant: —
| Benchmark | Claude Opus 4.6 | GPT-5.5 Instant |
|---|---|---|
| Terminal-Bench | 79.8% | — |
| APEX-Agents | 46.3% | — |
| Remote Labor Index | 4.2% | — |
| τ²-bench Banking | 27.3% | — |
| Cybench | 93% | — |
| DeepResearch Bench | 55.3% | — |
| GBAEval | 44.1% | — |
| LMArena Search | 1253 | — |
| METR Time Horizons | 78.9% | — |
| Vending-Bench 2 | 8,018 | — |
Reasoning Claude Opus 4.6 leads
Claude Opus 4.6: 57.8 (#23), GPT-5.5 Instant: 24.9 (#155)
| Benchmark | Claude Opus 4.6 | GPT-5.5 Instant |
|---|---|---|
| Chess Puzzles | 17% | 12% |
| LMArena Hard Prompts | 1527 | 1426 |
| Epoch Capabilities Index | 155.24 | 142.52 |
| ARC-AGI-2 | 69.2% | — |
| SimpleBench | 67.6% | — |
| Kagi LLM Benchmark | 83.6% | — |
| NYT Connections (extended) | 92.1% | — |
| ARC-AGI-1 | 94% | — |
| CritPt | — | 0% |
| EnigmaEval | 7.6% | — |
| Thematic Generalization | 80.6% | — |
| EBR-Bench | 12.7% | — |
| Mystery Game Puzzles | 25% | — |
| DTBench | 91.2% | — |
| LMCA | 55.8% | — |
| ForecastBench | 60 | — |
Math Claude Opus 4.6 leads
Claude Opus 4.6: 63.0 (#31), GPT-5.5 Instant: 26.5 (#259)
| Benchmark | Claude Opus 4.6 | GPT-5.5 Instant |
|---|---|---|
| FrontierMath (Tiers 1-3) | 66% | 26.3% |
| FrontierMath Tier 4 | 26.8% | 2.4% |
| OTIS Mock AIME 2024-2025 | 94.4% | 68.1% |
| LMArena Math | 1519 | 1420 |
| MathArena Final-Answer Competitions | 78.5% | — |
| ProofBench | 50% | — |
| FrontierMath (Feb 2025 set) | 40.7% | — |
| FrontierMath Tier 4 (v1) | 22.9% | — |
Knowledge Claude Opus 4.6 leads
Claude Opus 4.6: 61.9 (#26), GPT-5.5 Instant: 48.9 (#74)
| Benchmark | Claude Opus 4.6 | GPT-5.5 Instant |
|---|---|---|
| GPQA Diamond | 90.5% | 82.5% |
| LMArena Expert | 1546 | 1409 |
| Humanity's Last Exam | 34.4% | — |
| SimpleQA Verified | 47% | — |
| Vectara Hallucination Rate | 12.2% | — |
Multimodal GPT-5.5 Instant leads
Claude Opus 4.6: 37.3 (#74), GPT-5.5 Instant: 40.0 (#52)
| Benchmark | Claude Opus 4.6 | GPT-5.5 Instant |
|---|---|---|
| LMArena Vision | 1316 | 1250 |
| LMArena Document | 1507 | 1403 |
| Furniture Assembly | 28.3% | — |
Multilingual Claude Opus 4.6 leads
Claude Opus 4.6: 57.9 (#6), GPT-5.5 Instant: 52.8 (#80)
| Benchmark | Claude Opus 4.6 | GPT-5.5 Instant |
|---|---|---|
| LMArena Non-English | 1489 | 1417 |
| LMArena Chinese | 1551 | 1456 |
| LMArena French | 1513 | 1428 |
| LMArena German | 1502 | 1411 |
| LMArena Japanese | 1484 | 1408 |
| LMArena Korean | 1464 | 1392 |
| LMArena Russian | 1497 | 1431 |
| LMArena Spanish | 1510 | 1429 |
Instruction Following Claude Opus 4.6 leads
Claude Opus 4.6: 79.5 (#4), GPT-5.5 Instant: 74.2 (#100)
| Benchmark | Claude Opus 4.6 | GPT-5.5 Instant |
|---|---|---|
| LMArena Instruction Following | 1523 | 1406 |
Long Context Claude Opus 4.6 leads
Claude Opus 4.6: 48.1 (#13), GPT-5.5 Instant: 43.4 (#96)
| Benchmark | Claude Opus 4.6 | GPT-5.5 Instant |
|---|---|---|
| LMArena Longer Query | 1520 | 1422 |
| CL-bench | 20.7% | — |
| CL-bench Life | 17% | — |
Writing & Preference Claude Opus 4.6 leads
Claude Opus 4.6: 73.5 (#10), GPT-5.5 Instant: 61.8 (#85)
| Benchmark | Claude Opus 4.6 | GPT-5.5 Instant |
|---|---|---|
| LMArena Text | 1503 | 1419 |
| LMArena Creative Writing | 1505 | 1419 |
| LMArena Multi-Turn | 1513 | 1433 |
| EQ-Bench Creative Writing | 1809 | — |
| EQ-Bench 4 | 1223 | — |
Frequently asked questions
Is Claude Opus 4.6 better than GPT-5.5 Instant?
Claude Opus 4.6 is the stronger model overall, scoring 58.2 to 42.7 on the Noometry Index.
Is Claude Opus 4.6 or GPT-5.5 Instant better for coding?
Claude Opus 4.6 scores higher on coding benchmarks: 57.2 versus 44.3 in the Noometry coding category.
How many benchmarks do Claude Opus 4.6 and GPT-5.5 Instant share?
25 benchmarks have published results for both models. Claude Opus 4.6 has 68 scored results on Noometry and GPT-5.5 Instant has 27.