Claude Opus 5.5 vs Claude Sonnet 5.5
At 6,000 chat requests per month (1,500 in / 400 out), Claude Sonnet 5.5 costs $42 and Claude Opus 5.5 costs $84 — roughly 2.0× the spend.
| Spec | Claude Opus 5.5 | Claude Sonnet 5.5 |
|---|---|---|
| Vendor | Anthropic | Anthropic |
| Input / 1M tokens | $4 | $2 |
| Output / 1M tokens | $20 | $10 |
| Cached input / 1M | $0.200 | $0.100 |
| Context window | 1M tokens | 1M tokens |
| Max output | 128K tokens | 128K tokens |
| Input modalities | text, image | text, image |
| Released | — | — |
| Cost per 1M cached reads | $0.200 | $0.100 |
Published list prices, last verified Oct 15, 2026. Source links are on each model's page.
Cost at three workloads
| Workload | Claude Opus 5.5 | Claude Sonnet 5.5 | Difference |
|---|---|---|---|
| Customer-support reply (1,500 in / 400 out) | $0.014 | $0.0070 | Claude Sonnet 5.5 cheaper by $0.0070 |
| Document summary (20,000 in / 1,000 out) | $0.100 | $0.050 | Claude Sonnet 5.5 cheaper by $0.050 |
| Code review pass (8,000 in / 1,500 out) | $0.062 | $0.031 | Claude Sonnet 5.5 cheaper by $0.031 |
Which one fits your workload
- Long context: both accept 1M tokens, so context length does not separate them.
- Long answers: Claude Sonnet 5.5 has the lower output price ($10 vs $20 per million), which matters most when answers are long.
- High-volume, short answers: Claude Sonnet 5.5 is cheaper on input ($2 vs $4 per million).
- Caching: at least one of these vendors publishes a discounted cached-input rate; if you resend the same system prompt and context, model the cache-hit rate or you will overestimate cost.
This comparison uses published price and specification data only. It does not rank output quality — run your own evaluation on your own prompts before switching a production default.