# Claude 2.1 vs o3-pro

> o3-pro is the stronger model overall, scoring 42.9 to 25.2 on the Noometry Index.

- Canonical page: https://noometry.com/compare/claude-2-1-vs-o3-pro
- Last updated: 2026-10-10
- Shared benchmarks: 3

## Summary

- They share 3 benchmarks with published results for both. Claude 2.1 scores higher in 0 categories and o3-pro in 3 categories; 3 gaps are clear of the uncertainty.
- The widest gap is in coding, where o3-pro leads 55.5 to 26.2.
- The biggest single-benchmark swing is WeirdML: 7.1% for Claude 2.1 and 58.2% for o3-pro.

## Snapshot

| | Claude 2.1 | o3-pro |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 25.2 | 42.9 |
| Rank | 345 | 105 |
| Context | — | 200K |
| Input $/M | — | $20 |
| Output $/M | — | $80 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude 2.1: 26.2 (#327)
- o3-pro: 55.5 (#24)

| Benchmark | Claude 2.1 | o3-pro |
|---|---|---|
| WeirdML | 7.1% | 58.2% |
| Aider Polyglot | — | 84.9% |

## Reasoning

- Claude 2.1: 21.4 (#221)
- o3-pro: 23.8 (#171)

| Benchmark | Claude 2.1 | o3-pro |
|---|---|---|
| DTBench | 51% | 86.9% |
| Epoch Capabilities Index | 119.27 | 147.42 |
| ARC-AGI-2 | — | 4.9% |
| Kagi LLM Benchmark | — | 72.1% |
| ARC-AGI-1 | — | 59.3% |
| LMCA | — | 38.5% |
| ForecastBench | 54.2 | — |

## Math

- Claude 2.1: 10.2 (#315)
- o3-pro: —

| Benchmark | Claude 2.1 | o3-pro |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | — |

## Knowledge

- Claude 2.1: 15.4 (#292)
- o3-pro: 29.5 (#238)

| Benchmark | Claude 2.1 | o3-pro |
|---|---|---|
| GPQA Diamond | 33% | — |
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 23.3% |
| MMLU | 73.5% | — |

## Long Context

- Claude 2.1: —
- o3-pro: 72.2 (#1)

| Benchmark | Claude 2.1 | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |

## Writing & Preference

- Claude 2.1: —
- o3-pro: 57.1 (#133)

| Benchmark | Claude 2.1 | o3-pro |
|---|---|---|
| Short-Story Creative Writing | — | 84.4% |

## FAQ

### Is Claude 2.1 better than o3-pro?

o3-pro is the stronger model overall, scoring 42.9 to 25.2 on the Noometry Index.

### Is Claude 2.1 or o3-pro better for coding?

o3-pro scores higher on coding benchmarks: 55.5 versus 26.2 in the Noometry coding category.

### How many benchmarks do Claude 2.1 and o3-pro share?

3 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and o3-pro has 12.