Claude Opus 5.5 vs Claude Sonnet 5.5
30-second takeaway
- Claude Sonnet 5.5 has the cheaper input: $2 vs $4 (per 1M tokens, 50% less)
- Same context window (1M tokens)
| Claude Opus 5.5 AI/ML API | Claude Sonnet 5.5 AI/ML API | |
|---|---|---|
| Input | $4 | $2 |
| Output | $20 | $10 |
| Context | 1M | 1M |
More specs (max output / capabilities)
| max output | 128,000 | 128,000 |
| Reasoning | ✓ Yes | ✓ Yes |
| Tool calls | ✓ Yes | ✓ Yes |
| Open weights | — No | — No |
Prices are official/data-source rates (per 1M tokens), not what relays actually charge — relay prices vary with discounts and group multipliers. See methodology.