# Claude Sonnet 4.5 vs o3-mini

> Claude Sonnet 4.5 is the stronger model overall, scoring 44.1 to 36.7 on the Noometry Index. o3-mini costs 3.1× less per token, which makes it the better buy when Claude Sonnet 4.5's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/claude-sonnet-4-5-vs-o3-mini
- Last updated: 2026-10-11
- Shared benchmarks: 39

## Summary

- They share 39 benchmarks with published results for both. Claude Sonnet 4.5 scores higher in 8 categories and o3-mini in 1 category; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Claude Sonnet 4.5 leads 66.5 to 50.3.
- The biggest single-benchmark swing is Cybench: 60% for Claude Sonnet 4.5 and 22.5% for o3-mini.
- o3-mini is cheaper at $1.10 / $4.40 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.5.

## Snapshot

| | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 44.1 | 36.7 |
| Rank | 81 | 212 |
| Context | 200K | 200K |
| Input $/M | $3 | $1.10 |
| Output $/M | $15 | $4.40 |
| Weights | Proprietary | Proprietary |

## Coding

- Claude Sonnet 4.5: 47.3 (#61)
- o3-mini: 40.8 (#132)

| Benchmark | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| SciCode | 44.7% | 39.8% |
| GSO | 14.7% | 1.3% |
| WeirdML | 47.7% | 43.7% |
| LMArena Coding | 1489 | 1378 |
| SWE-bench Verified | 71.3% | — |
| SWE-bench Verified (bash only) | 71.4% | — |
| Aider Polyglot | — | 60.4% |
| LMArena WebDev | 1393 | — |
| SWE-bench Multilingual | 67% | — |
| LiveBench Coding | — | 82.7% |
| CadEval | — | 54% |
| ALE-Bench | 796.15 | — |
| AlgoTune | 1.52 | — |

## Agentic & Tool Use

- Claude Sonnet 4.5: 38.3 (#32)
- o3-mini: 29.6 (#84)

| Benchmark | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| Cybench | 60% | 22.5% |
| Terminal-Bench | 46.5% | — |
| Berkeley Function Calling Leaderboard | 73.2% | — |
| GDPval | 42.5% | — |
| Remote Labor Index | 2.1% | — |
| τ²-bench Airline | 72% | — |
| τ²-bench Banking | 25.3% | — |
| τ²-bench Retail | 72.4% | — |
| τ²-bench Telecom | 84.9% | — |
| DeepResearch Bench | 52.6% | — |
| OSWorld | 62.9% | — |
| LMArena Search | 1159 | — |
| METR Time Horizons | 67.4% | — |
| Vending-Bench 2 | 3,839 | — |

## Reasoning

- Claude Sonnet 4.5: 26.9 (#125)
- o3-mini: 16.3 (#305)

| Benchmark | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| ARC-AGI-2 | 13.6% | 3% |
| SimpleBench | 54.3% | 22.8% |
| ARC-AGI-1 | 63.7% | 34.5% |
| CritPt | 1.1% | 0.3% |
| Chess Puzzles | 12% | 17% |
| LMArena Hard Prompts | 1462 | 1366 |
| Mystery Game Puzzles | 17% | 7% |
| DTBench | 83.2% | 68.8% |
| LMCA | 38.8% | 19% |
| Epoch Capabilities Index | 146.84 | 140.34 |
| ForecastBench | 61.9 | 59.6 |
| Kagi LLM Benchmark | 57.9% | — |
| NYT Connections (extended) | 37.3% | — |
| EnigmaEval | 6% | — |
| EBR-Bench | 2.4% | — |
| LiveBench Reasoning | — | 89.6% |
| LiveBench Data Analysis | — | 70.6% |
| LiveBench | — | 75.9% |

## Math

- Claude Sonnet 4.5: 32.3 (#216)
- o3-mini: 28.1 (#244)

| Benchmark | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| FrontierMath (Tiers 1-3) | 23.9% | 18.6% |
| FrontierMath Tier 4 | 2.4% | 0% |
| OTIS Mock AIME 2024-2025 | 77.8% | 76.9% |
| LMArena Math | 1449 | 1396 |
| MATH Level 5 | 97.7% | 96.5% |
| FrontierMath (Feb 2025 set) | 15.2% | 12.4% |
| FrontierMath Tier 4 (v1) | 4.2% | 4.2% |
| ProofBench | 19% | — |
| Omni-MATH | 55.3% | — |
| LiveBench Math | — | 77.3% |

## Knowledge

- Claude Sonnet 4.5: 48.4 (#76)
- o3-mini: 38.3 (#146)

| Benchmark | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| GPQA Diamond | 82.3% | 77% |
| SimpleQA Verified | 30.7% | 15.3% |
| LMArena Expert | 1482 | 1364 |
| Humanity's Last Exam | 13.7% | — |
| MMLU-Pro | 86.9% | — |
| Confabulations | — | 17.9% |
| Vectara Hallucination Rate | 12% | — |
| GPQA (HELM) | 68.6% | — |

## Multimodal

- Claude Sonnet 4.5: 34.8 (#89)
- o3-mini: —

| Benchmark | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| VPCT | 39.8% | — |
| LMArena Document | 1450 | — |

## Multilingual

- Claude Sonnet 4.5: 53.4 (#69)
- o3-mini: 45.7 (#164)

| Benchmark | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| LMArena Non-English | 1425 | 1319 |
| LMArena Chinese | 1459 | 1379 |
| LMArena French | 1458 | 1334 |
| LMArena German | 1427 | 1303 |
| LMArena Japanese | 1390 | 1286 |
| LMArena Korean | 1403 | 1314 |
| LMArena Russian | 1437 | 1304 |
| LMArena Spanish | 1457 | 1321 |

## Instruction Following

- Claude Sonnet 4.5: 75.0 (#78)
- o3-mini: 75.1 (#72)

| Benchmark | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| LMArena Instruction Following | 1459 | 1337 |
| LiveBench Instruction Following | — | 84.4% |
| IFEval | 85% | — |

## Long Context

- Claude Sonnet 4.5: 45.2 (#46)
- o3-mini: 33.8 (#256)

| Benchmark | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| LMArena Longer Query | 1476 | 1343 |
| Fiction.LiveBench | — | 50% |

## Writing & Preference

- Claude Sonnet 4.5: 66.5 (#34)
- o3-mini: 50.3 (#182)

| Benchmark | Claude Sonnet 4.5 | o3-mini |
|---|---|---|
| LMArena Text | 1439 | 1337 |
| LMArena Creative Writing | 1442 | 1286 |
| LMArena Multi-Turn | 1465 | 1320 |
| Short-Story Creative Writing | — | 61.7% |
| EQ-Bench Creative Writing | 1678 | — |
| WildBench | 85.4% | — |
| LiveBench Language | — | 50.7% |

## FAQ

### Is Claude Sonnet 4.5 better than o3-mini?

Claude Sonnet 4.5 is the stronger model overall, scoring 44.1 to 36.7 on the Noometry Index. o3-mini costs 3.1× less per token, which makes it the better buy when Claude Sonnet 4.5's lead doesn't matter for your workload.

### Which is cheaper, Claude Sonnet 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 Sonnet 4.5 lists at $3 and $15.

### Is Claude Sonnet 4.5 or o3-mini better for coding?

Claude Sonnet 4.5 scores higher on coding benchmarks: 47.3 versus 40.8 in the Noometry coding category.

### Which has the bigger context window?

Both accept 200K tokens.

### How many benchmarks do Claude Sonnet 4.5 and o3-mini share?

39 benchmarks have published results for both models. Claude Sonnet 4.5 has 73 scored results on Noometry and o3-mini has 51.