Claude Opus 4.5 vs o3
Claude Opus 4.5 
o3 Verdict
- Claude Opus 4.5 (thinking) and o3 are level on quality (61.1 vs 61.6).
- Claude Opus 4.5 (thinking) is stronger in agents & tools, composite, knowledge, long context, multimodal.
- o3 is stronger in coding, instruction following, maths, reasoning, human preference.
- o3 is 2.9× cheaper ($3.50 vs $10.00 per 1M blended).
- o3 streams 2.3× faster (107 vs 46 tokens per second).
| Metric | Claude Opus 4.5 (thinking) | o3 |
|---|---|---|
| BenchLeader Index | 61.1 | 61.6 |
| Agents & tools score | 74.6 | 70.3 |
| Coding score | 60.5 | 62.0 |
| Composite score | 65.8 | 54.5 |
| Instruction following score | 54.8 | 65.0 |
| Knowledge score | 61.0 | 58.0 |
| Long context score | 65.2 | 63.8 |
| Maths score | 64.0 | 78.6 |
| Multimodal score | 58.0 | 57.9 |
| Reasoning score | 58.6 | 61.5 |
| Human preference score | – | 62.3 |
| Blended price $/M | $10.00 | $3.50 |
| Output speed | 46 tok/s | 107 tok/s |
| Time to first answer | 16.3 s | 6.3 s |
| Context window | 200k | 200k |
| Epoch Capabilities Index | – | 146.9 |
| LMArena Text | – | 1432 |
| LMArena Hard Prompts | – | 1441 |
| LMArena Coding | – | 1460 |
| LMArena Vision | – | 1214 |
| AA Intelligence Index | 29.1 | 20.2 |
| IFBench | 58.0% | 71.4% |
| AA-LCR | 77.3% | 74.7% |
| MMMU-Pro | 74.0% | 70.1% |
| AA-Omniscience | 14 | -15.6 |
| Terminal-Bench Hard | 47.0% | 37.1% |
| GPQA Diamond (AA) | 86.6% | 82.7% |
| Humanity's Last Exam (AA) | 30.1% | 20.1% |
| τ²-Bench Telecom (AA) | 89.5% | 80.7% |
| AIME (Vals) | 95.4% | – |
| LiveCodeBench | 83.7% | – |
| MMLU-Pro | 87.3% | – |
| LegalBench | 84.6% | – |
| CorpFin | 65.1% | – |
| TaxEval | 74.9% | – |
| MedQA | 95.9% | – |
| MGSM | 95.2% | – |
| SWE-bench (Vals) | 76.4% | – |
| GPQA Diamond (Vals) | 85.9% | – |
| MultiChallenge | 59.0% | – |
| PRBench Finance | 46.2% | 47.7% |
| PRBench Legal | 44.2% | 48.6% |
| VISTA | 46.4% | – |
| MultiNRC | 48.6% | – |
| TutorBench | 51.2% | – |
| MMMU (validation) | – | 82.9% |
| MMMU-Pro (official) | – | 76.4% |
| Kagi LLM Benchmark | 80.2% | 67.6% |
| IFEval (HELM) | – | 86.9% |
| Omni-MATH (HELM) | – | 71.4% |
| WildBench (HELM) | – | 86.1% |
| MMLU-Pro (HELM) | – | 85.9% |
| GPQA Diamond (HELM) | – | 75.3% |
| HELM Capabilities mean | – | 81.1% |
| Aider Polyglot | – | 81.3% |
| SWE-bench Verified (bash only) | – | 58.4% |
| SWE-bench Verified (any scaffold) | – | 58.4% |
| ARC-AGI-1 | 80.0% | – |
| ARC-AGI-2 | 37.6% | – |
| BFCL Overall | – | 63.0% |
Data as of 2026-09-12. Best configuration of each model; every score links to its source on the model pages.
Claude Opus 4.5 vs o3: questions
- Is Claude Opus 4.5 better than o3?
- Claude Opus 4.5 (thinking) and o3 are level on quality (61.1 vs 61.6). The BenchLeader Index combines every independent quality benchmark; o3 is ahead overall as of 2026-09-12, but check the category scores for your use.
- Is Claude Opus 4.5 better than o3 for coding?
- o3 scores higher in coding (62 vs 61 on the category index, where 50 is average).
- Is Claude Opus 4.5 better than o3 for agentic tasks?
- Claude Opus 4.5 scores higher in agentic tasks (75 vs 70 on the category index, where 50 is average).
- Which is cheaper, Claude Opus 4.5 or o3?
- o3 is cheaper: $3.50 against $10.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Opus 4.5 or o3?
- o3 streams faster: 107 against 46 output tokens per second.
- Which has the larger context window?
- Both accept 200k tokens of context.