Model comparison
Claude Opus 4 vs GPT-5.5 Instant
Claude Opus 4 and GPT-5.5 Instant score almost the same on the Noometry Index (42.9 vs 42.5), so choose on price, context window or the category you care about most.
Last verified . 22 shared benchmarks.
Summary
- They share 22 benchmarks with published results for both. Claude Opus 4 scores higher in 4 categories and GPT-5.5 Instant in 5 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Opus 4 leads 40.2 to 26.1.
- The biggest single-benchmark swing is GPQA Diamond: 76.3% for Claude Opus 4 and 82.5% for GPT-5.5 Instant.
Side by side
| Claude Opus 4 | GPT-5.5 Instant | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 42.9 | 42.5 |
| Released | 2025-05-22 | 2026-05-05 |
| Weights | Proprietary | Proprietary |
| Context window | 200K | — |
| Max output | 32K | — |
| Input $ / M tokens | $15 | — |
| Output $ / M tokens | $75 | — |
| Results tracked | 56 | 27 |
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Category by category
Coding Claude Opus 4 leads
Claude Opus 4: 47.8 (#55), GPT-5.5 Instant: 43.7 (#73)
| Benchmark | Claude Opus 4 | GPT-5.5 Instant |
|---|---|---|
| LMArena Coding | 1442 | 1433 |
| SWE-bench Verified | 70.7% | — |
| SWE-bench Verified (bash only) | 67.6% | — |
| Aider Polyglot | 72% | — |
| SciCode | — | 48.6% |
| GSO | 6.9% | — |
| WeirdML | 43.7% | — |
| AlgoTune | 1.33 | — |
Agentic & Tool Use Not comparable
Claude Opus 4: 34.5 (#39), GPT-5.5 Instant: —
| Benchmark | Claude Opus 4 | GPT-5.5 Instant |
|---|---|---|
| Cybench | 38% | — |
| DeepResearch Bench | 46.8% | — |
| LMArena Search | 1127 | — |
| METR Time Horizons | 63.9% | — |
Reasoning Claude Opus 4 leads
Claude Opus 4: 27.4 (#104), GPT-5.5 Instant: 24.2 (#149)
| Benchmark | Claude Opus 4 | GPT-5.5 Instant |
|---|---|---|
| CritPt | 0.3% | 0% |
| LMArena Hard Prompts | 1399 | 1426 |
| Epoch Capabilities Index | 142.67 | 142.48 |
| ARC-AGI-2 | 8.6% | — |
| SimpleBench | 58.8% | — |
| Kagi LLM Benchmark | 74.3% | — |
| ARC-AGI-1 | 35.7% | — |
| Chess Puzzles | — | 12% |
| EnigmaEval | 5.6% | — |
| DTBench | 81.6% | — |
| LMCA | 37.4% | — |
| ForecastBench | 61.1 | — |
Math Claude Opus 4 leads
Claude Opus 4: 40.2 (#80), GPT-5.5 Instant: 26.1 (#241)
| Benchmark | Claude Opus 4 | GPT-5.5 Instant |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 64.4% | 68.1% |
| LMArena Math | 1391 | 1420 |
| FrontierMath (Tiers 1-3) | — | 26.3% |
| FrontierMath Tier 4 | — | 2.4% |
| Omni-MATH | 61.6% | — |
| MATH Level 5 | 85% | — |
| FrontierMath (Feb 2025 set) | 4.5% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge GPT-5.5 Instant leads
Claude Opus 4: 43.9 (#82), GPT-5.5 Instant: 48.9 (#68)
| Benchmark | Claude Opus 4 | GPT-5.5 Instant |
|---|---|---|
| GPQA Diamond | 76.3% | 82.5% |
| LMArena Expert | 1384 | 1409 |
| Humanity's Last Exam | 10.7% | — |
| MMLU-Pro | 87.5% | — |
| Confabulations | 15.9% | — |
| Vectara Hallucination Rate | 12% | — |
| GPQA (HELM) | 70.8% | — |
Multimodal GPT-5.5 Instant leads
Claude Opus 4: 30.9 (#101), GPT-5.5 Instant: 39.3 (#48)
| Benchmark | Claude Opus 4 | GPT-5.5 Instant |
|---|---|---|
| LMArena Vision | 1192 | 1250 |
| GeoBench | 49% | — |
| VPCT | 38% | — |
| LMArena Document | — | 1403 |
Multilingual GPT-5.5 Instant leads
Claude Opus 4: 49.0 (#133), GPT-5.5 Instant: 53.0 (#76)
| Benchmark | Claude Opus 4 | GPT-5.5 Instant |
|---|---|---|
| LMArena Non-English | 1362 | 1417 |
| LMArena Chinese | 1386 | 1457 |
| LMArena French | 1370 | 1428 |
| LMArena German | 1391 | 1410 |
| LMArena Japanese | 1332 | 1408 |
| LMArena Korean | 1318 | 1393 |
| LMArena Russian | 1392 | 1430 |
| LMArena Spanish | 1388 | 1430 |
Instruction Following Claude Opus 4 leads
Claude Opus 4: 77.3 (#26), GPT-5.5 Instant: 74.4 (#94)
| Benchmark | Claude Opus 4 | GPT-5.5 Instant |
|---|---|---|
| LMArena Instruction Following | 1406 | 1407 |
| IFEval | 91.8% | — |
Long Context GPT-5.5 Instant leads
Claude Opus 4: 39.5 (#167), GPT-5.5 Instant: 43.4 (#92)
| Benchmark | Claude Opus 4 | GPT-5.5 Instant |
|---|---|---|
| LMArena Longer Query | 1422 | 1422 |
| Fiction.LiveBench | 61.1% | — |
Writing & Preference Too close to call
Claude Opus 4: 61.4 (#85), GPT-5.5 Instant: 62.0 (#81)
| Benchmark | Claude Opus 4 | GPT-5.5 Instant |
|---|---|---|
| LMArena Text | 1377 | 1419 |
| LMArena Creative Writing | 1386 | 1420 |
| LMArena Multi-Turn | 1396 | 1434 |
| Short-Story Creative Writing | 83.6% | — |
| EQ-Bench Creative Writing | 1580 | — |
| WildBench | 85.2% | — |
Frequently asked questions
Is Claude Opus 4 better than GPT-5.5 Instant?
Claude Opus 4 and GPT-5.5 Instant score almost the same on the Noometry Index (42.9 vs 42.5), so choose on price, context window or the category you care about most.
Is Claude Opus 4 or GPT-5.5 Instant better for coding?
Claude Opus 4 scores higher on coding benchmarks: 47.8 versus 43.7 in the Noometry coding category.
How many benchmarks do Claude Opus 4 and GPT-5.5 Instant share?
22 benchmarks have published results for both models. Claude Opus 4 has 56 scored results on Noometry and GPT-5.5 Instant has 27.