# Claude Opus 5.5 vs o3-pro

> Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 42.7 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-opus-5-5-vs-o3-pro
- Last updated: 2026-10-10
- Shared benchmarks: 4

## Summary

- They share 4 benchmarks with published results for both. Claude Opus 5.5 scores higher in 4 categories and o3-pro in 1 category; 5 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Opus 5.5 leads 79.5 to 24.1.
- The biggest single-benchmark swing is ARC-AGI-2: 92.5% for Claude Opus 5.5 and 4.9% for o3-pro.
- Claude Opus 5.5 is cheaper at $4 / $20 per million input/output tokens, against $20 / $80 for o3-pro.
- Claude Opus 5.5 accepts more context: 1M tokens versus 200K.

## Snapshot

| | Claude Opus 5.5 | o3-pro |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 68.5 | 42.7 |
| Rank | 3 | 94 |
| Context | 1M | 200K |
| Input $/M | $4 | $20 |
| Output $/M | $20 | $80 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Opus 5.5: 71.4 (#1)
- o3-pro: 55.1 (#22)

| Benchmark | Claude Opus 5.5 | o3-pro |
|---|---|---|
| FrontierCode | 54.4% | — |
| Aider Polyglot | — | 84.9% |
| CursorBench | 57.8% | — |
| LMArena WebDev | 1820 | — |
| FrontierSWE | 62.3% | — |
| SciCode | 66.9% | — |
| WeirdML | — | 58.2% |
| LMArena Coding | 1545 | — |
| MirrorCode | 77.4% | — |

## Agentic & Tool Use

- Claude Opus 5.5: 45.3 (#13)
- o3-pro: —

| Benchmark | Claude Opus 5.5 | o3-pro |
|---|---|---|
| APEX-Agents | 73.5% | — |
| GDP.pdf | 30.6% | — |

## Reasoning

- Claude Opus 5.5: 79.5 (#2)
- o3-pro: 24.1 (#152)

| Benchmark | Claude Opus 5.5 | o3-pro |
|---|---|---|
| ARC-AGI-2 | 92.5% | 4.9% |
| ARC-AGI-1 | 97.5% | 59.3% |
| DTBench | 98.9% | 86.9% |
| LMCA | 68.2% | 38.5% |
| Kagi LLM Benchmark | — | 72.1% |
| NYT Connections (extended) | 88.5% | — |
| CritPt | 31.7% | — |
| EBR-Bench | 71.4% | — |
| LMArena Hard Prompts | 1545 | — |
| Mystery Game Puzzles | 71% | — |
| Epoch Capabilities Index | — | 147.43 |

## Math

- Claude Opus 5.5: 92.4 (#2)
- o3-pro: —

| Benchmark | Claude Opus 5.5 | o3-pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | 91.2% | — |
| FrontierMath Tier 4 | 95% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 100% | — |

## Knowledge

- Claude Opus 5.5: 66.6 (#9)
- o3-pro: 29.0 (#234)

| Benchmark | Claude Opus 5.5 | o3-pro |
|---|---|---|
| GPQA Diamond | 90.6% | — |
| SimpleQA Verified | 72.2% | — |
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 23.3% |
| LMArena Expert | 1564 | — |

## Multimodal

- Claude Opus 5.5: 56.5 (#2)
- o3-pro: —

| Benchmark | Claude Opus 5.5 | o3-pro |
|---|---|---|
| Furniture Assembly | 83.3% | — |

## Multilingual

- Claude Opus 5.5: 59.8 (#1)
- o3-pro: —

| Benchmark | Claude Opus 5.5 | o3-pro |
|---|---|---|
| LMArena Non-English | 1513 | — |
| LMArena Chinese | 1572 | — |
| LMArena Russian | 1532 | — |

## Instruction Following

- Claude Opus 5.5: 80.1 (#2)
- o3-pro: —

| Benchmark | Claude Opus 5.5 | o3-pro |
|---|---|---|
| LMArena Instruction Following | 1535 | — |

## Long Context

- Claude Opus 5.5: 47.3 (#18)
- o3-pro: 72.1 (#1)

| Benchmark | Claude Opus 5.5 | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |
| LMArena Longer Query | 1540 | — |

## Writing & Preference

- Claude Opus 5.5: 78.7 (#3)
- o3-pro: 57.1 (#128)

| Benchmark | Claude Opus 5.5 | o3-pro |
|---|---|---|
| LMArena Text | 1518 | — |
| LMArena Creative Writing | 1538 | — |
| Short-Story Creative Writing | — | 84.4% |
| EQ-Bench Creative Writing | 2050 | — |
| LMArena Multi-Turn | 1520 | — |

## FAQ

### Is Claude Opus 5.5 better than o3-pro?

Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 42.7 on the Noometry Index.

### Which is cheaper, Claude Opus 5.5 or o3-pro?

Claude Opus 5.5 is cheaper. It lists at $4 per million input tokens and $20 per million output tokens; o3-pro lists at $20 and $80.

### Is Claude Opus 5.5 or o3-pro better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.4 versus 55.1 in the Noometry coding category.

### Which has the bigger context window?

Claude Opus 5.5 does, with 1M tokens against 200K.

### How many benchmarks do Claude Opus 5.5 and o3-pro share?

4 benchmarks have published results for both models. Claude Opus 5.5 has 35 scored results on Noometry and o3-pro has 12.