Model comparison
Claude 2.1 vs o3
o3 is the stronger model overall, scoring 47.5 to 25.2 on the Noometry Index.
Last verified . 6 shared benchmarks.
Summary
- They share 6 benchmarks with published results for both. Claude 2.1 scores higher in 0 categories and o3 in 4 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where o3 leads 50.2 to 10.2.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 1.9% for Claude 2.1 and 84.4% for o3.
Side by side
| Claude 2.1 | o3 | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 25.2 | 47.5 |
| Released | 2023-11-21 | 2025-04-16 |
| Weights | Proprietary | Proprietary |
| Context window | — | 200K |
| Max output | — | 100K |
| Input $ / M tokens | — | $2 |
| Output $ / M tokens | — | $8 |
| Results tracked | 7 | 63 |
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Category by category
Coding o3 leads
Claude 2.1: 26.2 (#327), o3: 46.8 (#64)
| Benchmark | Claude 2.1 | o3 |
|---|---|---|
| WeirdML | 7.1% | 52.4% |
| SWE-bench Verified | — | 62.3% |
| SWE-bench Verified (bash only) | — | 58.4% |
| Aider Polyglot | — | 81.3% |
| GSO | — | 8.8% |
| LMArena Coding | — | 1408 |
| CadEval | — | 74% |
| ALE-Bench | — | 933.55 |
Agentic & Tool Use Not comparable
Claude 2.1: —, o3: 34.5 (#44)
| Benchmark | Claude 2.1 | o3 |
|---|---|---|
| Berkeley Function Calling Leaderboard | — | 63% |
| GDPval | — | 30.8% |
| DeepResearch Bench | — | 45.2% |
| OSWorld | — | 23% |
| LMArena Search | — | 1144 |
| METR Time Horizons | — | 65.4% |
Reasoning o3 leads
Claude 2.1: 21.4 (#221), o3: 32.0 (#78)
| Benchmark | Claude 2.1 | o3 |
|---|---|---|
| DTBench | 51% | 84.8% |
| Epoch Capabilities Index | 119.27 | 146.86 |
| ForecastBench | 54.2 | 62.5 |
| ARC-AGI-2 | — | 6.5% |
| SimpleBench | — | 53.1% |
| Kagi LLM Benchmark | — | 67.6% |
| ARC-AGI-1 | — | 60.8% |
| CritPt | — | 1.4% |
| Chess Puzzles | — | 38% |
| EnigmaEval | — | 13.1% |
| LMArena Hard Prompts | — | 1402 |
| Mystery Game Puzzles | — | 29% |
| LMCA | — | 39.7% |
Math o3 leads
Claude 2.1: 10.2 (#315), o3: 50.2 (#58)
| Benchmark | Claude 2.1 | o3 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 1.9% | 84.4% |
| FrontierMath (Tiers 1-3) | — | 33.3% |
| Omni-MATH | — | 71.4% |
| LMArena Math | — | 1426 |
| MATH Level 5 | — | 97.8% |
| FrontierMath (Feb 2025 set) | — | 18.7% |
| FrontierMath Tier 4 (v1) | — | 2.1% |
Knowledge o3 leads
Claude 2.1: 15.4 (#292), o3: 54.6 (#52)
| Benchmark | Claude 2.1 | o3 |
|---|---|---|
| GPQA Diamond | 33% | 81.8% |
| Humanity's Last Exam | — | 20.3% |
| SimpleQA Verified | — | 49.4% |
| MMLU-Pro | — | 85.9% |
| Confabulations | — | 14.4% |
| GPQA (HELM) | — | 75.3% |
| LMArena Expert | — | 1402 |
| MMLU | 73.5% | — |
Multimodal Not comparable
Claude 2.1: —, o3: 41.4 (#36)
| Benchmark | Claude 2.1 | o3 |
|---|---|---|
| LMArena Vision | — | 1214 |
| GeoBench | — | 74% |
| VPCT | — | 52% |
Multilingual Not comparable
Claude 2.1: —, o3: 51.7 (#105)
| Benchmark | Claude 2.1 | o3 |
|---|---|---|
| LMArena Non-English | — | 1401 |
| LMArena Chinese | — | 1437 |
| LMArena French | — | 1430 |
| LMArena German | — | 1420 |
| LMArena Japanese | — | 1403 |
| LMArena Korean | — | 1370 |
| LMArena Russian | — | 1406 |
| LMArena Spanish | — | 1395 |
Instruction Following Not comparable
Claude 2.1: —, o3: 72.8 (#127)
| Benchmark | Claude 2.1 | o3 |
|---|---|---|
| IFEval | — | 86.9% |
| LMArena Instruction Following | — | 1368 |
Long Context Not comparable
Claude 2.1: —, o3: 53.3 (#6)
| Benchmark | Claude 2.1 | o3 |
|---|---|---|
| Fiction.LiveBench | — | 88.9% |
| CL-bench | — | 17.8% |
| LMArena Longer Query | — | 1372 |
Writing & Preference Not comparable
Claude 2.1: —, o3: 63.5 (#64)
| Benchmark | Claude 2.1 | o3 |
|---|---|---|
| LMArena Text | — | 1410 |
| LMArena Creative Writing | — | 1359 |
| Short-Story Creative Writing | — | 83.9% |
| EQ-Bench Creative Writing | — | 1676 |
| WildBench | — | 86.1% |
| LMArena Multi-Turn | — | 1405 |
Frequently asked questions
Is Claude 2.1 better than o3?
o3 is the stronger model overall, scoring 47.5 to 25.2 on the Noometry Index.
Is Claude 2.1 or o3 better for coding?
o3 scores higher on coding benchmarks: 46.8 versus 26.2 in the Noometry coding category.
How many benchmarks do Claude 2.1 and o3 share?
6 benchmarks have published results for both models. Claude 2.1 has 7 scored results on Noometry and o3 has 63.