Model comparison
Claude 2.1 vs o3-pro
o3-pro is the stronger model overall, scoring 42.9 to 25.2 on the Noometry Index.
Last verified . 3 shared benchmarks.
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.
Side by side
| Claude 2.1 | o3-pro | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 25.2 | 42.9 |
| Released | 2023-11-21 | 2025-06-10 |
| Weights | Proprietary | Proprietary |
| Context window | — | 200K |
| Max output | — | 100K |
| Input $ / M tokens | — | $20 |
| Output $ / M tokens | — | $80 |
| Results tracked | 7 | 12 |
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Category by category
Coding o3-pro leads
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 o3-pro leads
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 Not comparable
Claude 2.1: 10.2 (#315), o3-pro: —
| Benchmark | Claude 2.1 | o3-pro |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | — |
Knowledge o3-pro leads
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 Not comparable
Claude 2.1: —, o3-pro: 72.2 (#1)
| Benchmark | Claude 2.1 | o3-pro |
|---|---|---|
| Fiction.LiveBench | — | 97.2% |
Writing & Preference Not comparable
Claude 2.1: —, o3-pro: 57.1 (#133)
| Benchmark | Claude 2.1 | o3-pro |
|---|---|---|
| Short-Story Creative Writing | — | 84.4% |
Frequently asked questions
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.