Claude 4.6 Sonnet vs o3
Direct spec comparison of Claude 4.6 Sonnet (from Anthropic) and o3 (from OpenAI). Want a 3- or 4-way comparison? Open the multi-model tool →
 Claude 4.6 SonnetAnthropic |  o3OpenAI | |
|---|---|---|
| Vendor | Anthropic | OpenAI |
| Family | Claude | o-series |
| Release date | 2026-02-17 | 2025-04-16 |
| Context window | 1,000,000 tokens | 200,000 tokens |
| Parameters | — | — |
| Modality | text, vision | text, vision |
| License | proprietary | proprietary |
| Source | proprietary | proprietary |
| Description | Anthropic's mid-tier flagship — released 12 days after Opus 4.6 and matching most of its capabilities at ~40% the API cost ($3/$15 per 1M tokens). 1M-token context. | Reasoning-focused model in the o-series. |
| Links | ||
| Benchmarks | ||
| MMLU-Pro | 85.4% | — |
| GPQA-D | 85.8% | 87.7% |
| HumanEval | 95.9% | — |
| Aider | 83.6% | — |
| AIME-25 | 87.4% | 88.9% |
| LiveCB | 73.8% | — |
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