Model comparison
Claude Opus 4.5 vs o3
Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 47.5 on the Noometry Index. o3 costs 2.9× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.
Last verified . 50 shared benchmarks.
Summary
- They share 50 benchmarks with published results for both. Claude Opus 4.5 scores higher in 7 categories and o3 in 3 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in agentic & tool use, where Claude Opus 4.5 leads 47.3 to 34.5.
- The biggest single-benchmark swing is OSWorld: 66.3% for Claude Opus 4.5 and 23% for o3.
- o3 is cheaper at $2 / $8 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
Side by side
| Claude Opus 4.5 | o3 | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 50.5 | 47.5 |
| Released | 2025-11-01 | 2025-04-16 |
| Weights | Proprietary | Proprietary |
| Context window | 200K | 200K |
| Max output | 64K | 100K |
| Input $ / M tokens | $5 | $2 |
| Output $ / M tokens | $25 | $8 |
| Results tracked | 69 | 63 |
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Category by category
Coding Claude Opus 4.5 leads
Claude Opus 4.5: 54.8 (#27), o3: 46.8 (#64)
| Benchmark | Claude Opus 4.5 | o3 |
|---|---|---|
| SWE-bench Verified | 76.7% | 62.3% |
| SWE-bench Verified (bash only) | 76.8% | 58.4% |
| GSO | 26.5% | 8.8% |
| WeirdML | 63.7% | 52.4% |
| LMArena Coding | 1504 | 1408 |
| ALE-Bench | 1,025 | 933.55 |
| Aider Polyglot | — | 81.3% |
| LMArena WebDev | 1494 | — |
| SWE-bench Multilingual | 70.7% | — |
| CadEval | — | 74% |
| AlgoTune | 1.77 | — |
Agentic & Tool Use Claude Opus 4.5 leads
Claude Opus 4.5: 47.3 (#12), o3: 34.5 (#44)
| Benchmark | Claude Opus 4.5 | o3 |
|---|---|---|
| Berkeley Function Calling Leaderboard | 77.5% | 63% |
| GDPval | 45.5% | 30.8% |
| DeepResearch Bench | 54.8% | 45.2% |
| OSWorld | 66.3% | 23% |
| LMArena Search | 1180 | 1144 |
| METR Time Horizons | 75% | 65.4% |
| Terminal-Bench | 63.1% | — |
| Remote Labor Index | 3.8% | — |
| τ²-bench Airline | 84% | — |
| τ²-bench Banking | 24.7% | — |
| τ²-bench Retail | 79.6% | — |
| τ²-bench Telecom | 92.3% | — |
| Cybench | 82% | — |
| BALROG | 43.5% | — |
| Vending-Bench 2 | 4,967 | — |
Reasoning Claude Opus 4.5 leads
Claude Opus 4.5: 42.6 (#51), o3: 32.0 (#78)
| Benchmark | Claude Opus 4.5 | o3 |
|---|---|---|
| ARC-AGI-2 | 37.6% | 6.5% |
| SimpleBench | 62% | 53.1% |
| Kagi LLM Benchmark | 80.2% | 67.6% |
| ARC-AGI-1 | 80% | 60.8% |
| Chess Puzzles | 12% | 38% |
| EnigmaEval | 11.9% | 13.1% |
| LMArena Hard Prompts | 1476 | 1402 |
| Mystery Game Puzzles | 22% | 29% |
| DTBench | 89.9% | 84.8% |
| LMCA | 44.5% | 39.7% |
| Epoch Capabilities Index | 150.09 | 146.86 |
| ForecastBench | 60.7 | 62.5 |
| NYT Connections (extended) | 52.5% | — |
| CritPt | — | 1.4% |
| EBR-Bench | 14.3% | — |
Math o3 leads
Claude Opus 4.5: 38.6 (#132), o3: 50.2 (#58)
| Benchmark | Claude Opus 4.5 | o3 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 34.4% | 33.3% |
| OTIS Mock AIME 2024-2025 | 86.1% | 84.4% |
| LMArena Math | 1463 | 1426 |
| FrontierMath (Feb 2025 set) | 20.7% | 18.7% |
| FrontierMath Tier 4 (v1) | 4.2% | 2.1% |
| FrontierMath Tier 4 | 4.9% | — |
| ProofBench | 36% | — |
| Omni-MATH | — | 71.4% |
| MATH Level 5 | — | 97.8% |
Knowledge Claude Opus 4.5 leads
Claude Opus 4.5: 56.5 (#44), o3: 54.6 (#52)
| Benchmark | Claude Opus 4.5 | o3 |
|---|---|---|
| GPQA Diamond | 86% | 81.8% |
| Humanity's Last Exam | 25.2% | 20.3% |
| SimpleQA Verified | 45.7% | 49.4% |
| LMArena Expert | 1487 | 1402 |
| MMLU-Pro | — | 85.9% |
| Confabulations | — | 14.4% |
| Vectara Hallucination Rate | 10.9% | — |
| GPQA (HELM) | — | 75.3% |
Multimodal o3 leads
Claude Opus 4.5: 31.4 (#107), o3: 41.4 (#36)
| Benchmark | Claude Opus 4.5 | o3 |
|---|---|---|
| GeoBench | 75% | 74% |
| VPCT | 40% | 52% |
| LMArena Vision | — | 1214 |
| Furniture Assembly | 28.3% | — |
| LMArena Document | 1462 | — |
Multilingual Claude Opus 4.5 leads
Claude Opus 4.5: 54.3 (#47), o3: 51.7 (#105)
| Benchmark | Claude Opus 4.5 | o3 |
|---|---|---|
| LMArena Non-English | 1438 | 1401 |
| LMArena Chinese | 1470 | 1437 |
| LMArena French | 1471 | 1430 |
| LMArena German | 1449 | 1420 |
| LMArena Japanese | 1416 | 1403 |
| LMArena Korean | 1424 | 1370 |
| LMArena Russian | 1447 | 1406 |
| LMArena Spanish | 1458 | 1395 |
Instruction Following Claude Opus 4.5 leads
Claude Opus 4.5: 77.5 (#19), o3: 72.8 (#127)
| Benchmark | Claude Opus 4.5 | o3 |
|---|---|---|
| LMArena Instruction Following | 1478 | 1368 |
| IFEval | — | 86.9% |
Long Context o3 leads
Claude Opus 4.5: 46.5 (#22), o3: 53.3 (#6)
| Benchmark | Claude Opus 4.5 | o3 |
|---|---|---|
| CL-bench | 21.1% | 17.8% |
| LMArena Longer Query | 1480 | 1372 |
| Fiction.LiveBench | — | 88.9% |
Writing & Preference Claude Opus 4.5 leads
Claude Opus 4.5: 68.1 (#28), o3: 63.5 (#64)
| Benchmark | Claude Opus 4.5 | o3 |
|---|---|---|
| LMArena Text | 1451 | 1410 |
| LMArena Creative Writing | 1445 | 1359 |
| EQ-Bench Creative Writing | 1687 | 1676 |
| LMArena Multi-Turn | 1466 | 1405 |
| Short-Story Creative Writing | — | 83.9% |
| WildBench | — | 86.1% |
Frequently asked questions
Is Claude Opus 4.5 better than o3?
Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 47.5 on the Noometry Index. o3 costs 2.9× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.
Which is cheaper, Claude Opus 4.5 or o3?
o3 is cheaper. It lists at $2 per million input tokens and $8 per million output tokens; Claude Opus 4.5 lists at $5 and $25.
Is Claude Opus 4.5 or o3 better for coding?
Claude Opus 4.5 scores higher on coding benchmarks: 54.8 versus 46.8 in the Noometry coding category.
Which has the bigger context window?
Both accept 200K tokens.
How many benchmarks do Claude Opus 4.5 and o3 share?
50 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and o3 has 63.