# GPT-5.5 Instant vs o3-pro

> GPT-5.5 Instant and o3-pro score almost the same on the Noometry Index (42.5 vs 42.7), so choose on price, context window or the category you care about most.

- Canonical page: https://noometry.com/compare/gpt-5-5-instant-vs-o3-pro
- Last updated: 2026-10-10
- Shared benchmarks: 1

## 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; 4 gaps are clear of the uncertainty.
- The widest gap is in long context, where o3-pro leads 72.1 to 43.4.

## Snapshot

| | GPT-5.5 Instant | o3-pro |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Noometry Index | 42.5 | 42.7 |
| Rank | 99 | 94 |
| Context | — | 200K |
| Input $/M | — | $20 |
| Output $/M | — | $80 |
| Weights | Proprietary | Proprietary |

## Coding

- GPT-5.5 Instant: 43.7 (#73)
- o3-pro: 55.1 (#22)

| 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: 24.2 (#149)
- o3-pro: 24.1 (#152)

| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| Epoch Capabilities Index | 142.48 | 147.43 |
| 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

- GPT-5.5 Instant: 26.1 (#241)
- 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: 48.9 (#68)
- o3-pro: 29.0 (#234)

| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| GPQA Diamond | 82.5% | — |
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 23.3% |
| LMArena Expert | 1409 | — |

## Multimodal

- GPT-5.5 Instant: 39.3 (#48)
- o3-pro: —

| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| LMArena Vision | 1250 | — |
| LMArena Document | 1403 | — |

## Multilingual

- GPT-5.5 Instant: 53.0 (#76)
- o3-pro: —

| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| LMArena Non-English | 1417 | — |
| LMArena Chinese | 1457 | — |
| LMArena French | 1428 | — |
| LMArena German | 1410 | — |
| LMArena Japanese | 1408 | — |
| LMArena Korean | 1393 | — |
| LMArena Russian | 1430 | — |
| LMArena Spanish | 1430 | — |

## Instruction Following

- GPT-5.5 Instant: 74.4 (#94)
- o3-pro: —

| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| LMArena Instruction Following | 1407 | — |

## Long Context

- GPT-5.5 Instant: 43.4 (#92)
- o3-pro: 72.1 (#1)

| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |
| LMArena Longer Query | 1422 | — |

## Writing & Preference

- GPT-5.5 Instant: 62.0 (#81)
- o3-pro: 57.1 (#128)

| Benchmark | GPT-5.5 Instant | o3-pro |
|---|---|---|
| LMArena Text | 1419 | — |
| LMArena Creative Writing | 1420 | — |
| Short-Story Creative Writing | — | 84.4% |
| LMArena Multi-Turn | 1434 | — |

## FAQ

### Is GPT-5.5 Instant better than o3-pro?

GPT-5.5 Instant and o3-pro score almost the same on the Noometry Index (42.5 vs 42.7), 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: 55.1 versus 43.7 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.