Model comparison
Claude Opus 4.5 vs o3-mini
Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 36.7 on the Noometry Index. o3-mini costs 5.2× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.
Last verified . 36 shared benchmarks.
Summary
- They share 36 benchmarks with published results for both. Claude Opus 4.5 scores higher in 9 categories and o3-mini in 0 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Opus 4.5 leads 42.6 to 16.3.
- The biggest single-benchmark swing is Cybench: 82% for Claude Opus 4.5 and 22.5% for o3-mini.
- o3-mini is cheaper at $1.10 / $4.40 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
Side by side
| Claude Opus 4.5 | o3-mini | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 50.5 | 36.7 |
| Released | 2025-11-01 | 2024-12-20 |
| Weights | Proprietary | Proprietary |
| Context window | 200K | 200K |
| Max output | 64K | 100K |
| Input $ / M tokens | $5 | $1.10 |
| Output $ / M tokens | $25 | $4.40 |
| Results tracked | 69 | 51 |
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Category by category
Coding Claude Opus 4.5 leads
Claude Opus 4.5: 54.8 (#27), o3-mini: 40.8 (#132)
| Benchmark | Claude Opus 4.5 | o3-mini |
|---|---|---|
| GSO | 26.5% | 1.3% |
| WeirdML | 63.7% | 43.7% |
| LMArena Coding | 1504 | 1378 |
| SWE-bench Verified | 76.7% | — |
| SWE-bench Verified (bash only) | 76.8% | — |
| Aider Polyglot | — | 60.4% |
| LMArena WebDev | 1494 | — |
| SWE-bench Multilingual | 70.7% | — |
| SciCode | — | 39.8% |
| LiveBench Coding | — | 82.7% |
| CadEval | — | 54% |
| ALE-Bench | 1,025 | — |
| AlgoTune | 1.77 | — |
Agentic & Tool Use Claude Opus 4.5 leads
Claude Opus 4.5: 47.3 (#12), o3-mini: 29.6 (#84)
| Benchmark | Claude Opus 4.5 | o3-mini |
|---|---|---|
| Cybench | 82% | 22.5% |
| Terminal-Bench | 63.1% | — |
| Berkeley Function Calling Leaderboard | 77.5% | — |
| GDPval | 45.5% | — |
| Remote Labor Index | 3.8% | — |
| τ²-bench Airline | 84% | — |
| τ²-bench Banking | 24.7% | — |
| τ²-bench Retail | 79.6% | — |
| τ²-bench Telecom | 92.3% | — |
| DeepResearch Bench | 54.8% | — |
| OSWorld | 66.3% | — |
| BALROG | 43.5% | — |
| LMArena Search | 1180 | — |
| METR Time Horizons | 75% | — |
| Vending-Bench 2 | 4,967 | — |
Reasoning Claude Opus 4.5 leads
Claude Opus 4.5: 42.6 (#51), o3-mini: 16.3 (#305)
| Benchmark | Claude Opus 4.5 | o3-mini |
|---|---|---|
| ARC-AGI-2 | 37.6% | 3% |
| SimpleBench | 62% | 22.8% |
| ARC-AGI-1 | 80% | 34.5% |
| Chess Puzzles | 12% | 17% |
| LMArena Hard Prompts | 1476 | 1366 |
| Mystery Game Puzzles | 22% | 7% |
| DTBench | 89.9% | 68.8% |
| LMCA | 44.5% | 19% |
| Epoch Capabilities Index | 150.09 | 140.34 |
| ForecastBench | 60.7 | 59.6 |
| Kagi LLM Benchmark | 80.2% | — |
| NYT Connections (extended) | 52.5% | — |
| CritPt | — | 0.3% |
| EnigmaEval | 11.9% | — |
| EBR-Bench | 14.3% | — |
| LiveBench Reasoning | — | 89.6% |
| LiveBench Data Analysis | — | 70.6% |
| LiveBench | — | 75.9% |
Math Claude Opus 4.5 leads
Claude Opus 4.5: 38.6 (#132), o3-mini: 28.1 (#244)
| Benchmark | Claude Opus 4.5 | o3-mini |
|---|---|---|
| FrontierMath (Tiers 1-3) | 34.4% | 18.6% |
| FrontierMath Tier 4 | 4.9% | 0% |
| OTIS Mock AIME 2024-2025 | 86.1% | 76.9% |
| LMArena Math | 1463 | 1396 |
| FrontierMath (Feb 2025 set) | 20.7% | 12.4% |
| FrontierMath Tier 4 (v1) | 4.2% | 4.2% |
| ProofBench | 36% | — |
| LiveBench Math | — | 77.3% |
| MATH Level 5 | — | 96.5% |
Knowledge Claude Opus 4.5 leads
Claude Opus 4.5: 56.5 (#44), o3-mini: 38.3 (#146)
| Benchmark | Claude Opus 4.5 | o3-mini |
|---|---|---|
| GPQA Diamond | 86% | 77% |
| SimpleQA Verified | 45.7% | 15.3% |
| LMArena Expert | 1487 | 1364 |
| Humanity's Last Exam | 25.2% | — |
| Confabulations | — | 17.9% |
| Vectara Hallucination Rate | 10.9% | — |
Multimodal Not comparable
Claude Opus 4.5: 31.4 (#107), o3-mini: —
| Benchmark | Claude Opus 4.5 | o3-mini |
|---|---|---|
| GeoBench | 75% | — |
| VPCT | 40% | — |
| Furniture Assembly | 28.3% | — |
| LMArena Document | 1462 | — |
Multilingual Claude Opus 4.5 leads
Claude Opus 4.5: 54.3 (#47), o3-mini: 45.7 (#164)
| Benchmark | Claude Opus 4.5 | o3-mini |
|---|---|---|
| LMArena Non-English | 1438 | 1319 |
| LMArena Chinese | 1470 | 1379 |
| LMArena French | 1471 | 1334 |
| LMArena German | 1449 | 1303 |
| LMArena Japanese | 1416 | 1286 |
| LMArena Korean | 1424 | 1314 |
| LMArena Russian | 1447 | 1304 |
| LMArena Spanish | 1458 | 1321 |
Instruction Following Claude Opus 4.5 leads
Claude Opus 4.5: 77.5 (#19), o3-mini: 75.1 (#72)
| Benchmark | Claude Opus 4.5 | o3-mini |
|---|---|---|
| LMArena Instruction Following | 1478 | 1337 |
| LiveBench Instruction Following | — | 84.4% |
Long Context Claude Opus 4.5 leads
Claude Opus 4.5: 46.5 (#22), o3-mini: 33.8 (#256)
| Benchmark | Claude Opus 4.5 | o3-mini |
|---|---|---|
| LMArena Longer Query | 1480 | 1343 |
| Fiction.LiveBench | — | 50% |
| CL-bench | 21.1% | — |
Writing & Preference Claude Opus 4.5 leads
Claude Opus 4.5: 68.1 (#28), o3-mini: 50.3 (#182)
| Benchmark | Claude Opus 4.5 | o3-mini |
|---|---|---|
| LMArena Text | 1451 | 1337 |
| LMArena Creative Writing | 1445 | 1286 |
| LMArena Multi-Turn | 1466 | 1320 |
| Short-Story Creative Writing | — | 61.7% |
| EQ-Bench Creative Writing | 1687 | — |
| LiveBench Language | — | 50.7% |
Frequently asked questions
Is Claude Opus 4.5 better than o3-mini?
Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 36.7 on the Noometry Index. o3-mini costs 5.2× 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-mini?
o3-mini is cheaper. It lists at $1.10 per million input tokens and $4.40 per million output tokens; Claude Opus 4.5 lists at $5 and $25.
Is Claude Opus 4.5 or o3-mini better for coding?
Claude Opus 4.5 scores higher on coding benchmarks: 54.8 versus 40.8 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-mini share?
36 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and o3-mini has 51.