Model comparison
GPT-5.5 Instant vs o3-pro
GPT-5.5 Instant and o3-pro score almost the same on the Noometry Index (42.7 vs 42.9), so choose on price, context window or the category you care about most.
Last verified . 1 shared benchmarks.
Summary
- They share 1 benchmark with published results for both. GPT-5.5 Instant scores higher in 3 categories and o3-pro in 2 categories; 5 gaps are clear of the uncertainty.
- The widest gap is in long context, where o3-pro leads 72.2 to 43.4.
Side by side
| GPT-5.5 Instant | o3-pro | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 42.7 | 42.9 |
| Released | 2026-05-05 | 2025-06-10 |
| Weights | Proprietary | Proprietary |
| Context window | — | 200K |
| Max output | — | 100K |
| Input $ / M tokens | — | $20 |
| Output $ / M tokens | — | $80 |
| Results tracked | 27 | 12 |
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Category by category
Coding o3-pro leads
GPT-5.5 Instant: 44.3 (#74), o3-pro: 55.5 (#24)
| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| Aider Polyglot | — | 84.9% |
| SciCode | 48.6% | — |
| WeirdML | — | 58.2% |
| LMArena Coding | 1433 | — |
Reasoning GPT-5.5 Instant leads
GPT-5.5 Instant: 24.9 (#155), o3-pro: 23.8 (#171)
| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| Epoch Capabilities Index | 142.52 | 147.42 |
| ARC-AGI-2 | — | 4.9% |
| Kagi LLM Benchmark | — | 72.1% |
| ARC-AGI-1 | — | 59.3% |
| CritPt | 0% | — |
| Chess Puzzles | 12% | — |
| LMArena Hard Prompts | 1426 | — |
| DTBench | — | 86.9% |
| LMCA | — | 38.5% |
Math Not comparable
GPT-5.5 Instant: 26.5 (#259), o3-pro: —
| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | 26.3% | — |
| FrontierMath Tier 4 | 2.4% | — |
| OTIS Mock AIME 2024-2025 | 68.1% | — |
| LMArena Math | 1420 | — |
Knowledge GPT-5.5 Instant leads
GPT-5.5 Instant: 48.9 (#74), o3-pro: 29.5 (#238)
| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| GPQA Diamond | 82.5% | — |
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 23.3% |
| LMArena Expert | 1409 | — |
Multimodal Not comparable
GPT-5.5 Instant: 40.0 (#52), o3-pro: —
| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| LMArena Vision | 1250 | — |
| LMArena Document | 1403 | — |
Multilingual Not comparable
GPT-5.5 Instant: 52.8 (#80), o3-pro: —
| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| LMArena Non-English | 1417 | — |
| LMArena Chinese | 1456 | — |
| LMArena French | 1428 | — |
| LMArena German | 1411 | — |
| LMArena Japanese | 1408 | — |
| LMArena Korean | 1392 | — |
| LMArena Russian | 1431 | — |
| LMArena Spanish | 1429 | — |
Instruction Following Not comparable
GPT-5.5 Instant: 74.2 (#100), o3-pro: —
| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| LMArena Instruction Following | 1406 | — |
Long Context o3-pro leads
GPT-5.5 Instant: 43.4 (#96), o3-pro: 72.2 (#1)
| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |
| LMArena Longer Query | 1422 | — |
Writing & Preference GPT-5.5 Instant leads
GPT-5.5 Instant: 61.8 (#85), o3-pro: 57.1 (#133)
| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| LMArena Text | 1419 | — |
| LMArena Creative Writing | 1419 | — |
| Short-Story Creative Writing | — | 84.4% |
| LMArena Multi-Turn | 1433 | — |
Frequently asked questions
Is GPT-5.5 Instant better than o3-pro?
GPT-5.5 Instant and o3-pro score almost the same on the Noometry Index (42.7 vs 42.9), so choose on price, context window or the category you care about most.
Is GPT-5.5 Instant or o3-pro better for coding?
o3-pro scores higher on coding benchmarks: 55.5 versus 44.3 in the Noometry coding category.
How many benchmarks do GPT-5.5 Instant and o3-pro share?
1 benchmark has published results for both models. GPT-5.5 Instant has 27 scored results on Noometry and o3-pro has 12.