Compare models
Put up to 4 models beside each other — token prices, context windows, capabilities and provider, from the same catalogue the model pages read.
| Attribute | Claude Opus 5.5claude-opus-5.5 | S2.1 Pros2.1-pro |
|---|---|---|
| Pricing | ||
| Input | $4.00 / 1M | $0 / 1M |
| Output | $20.00 / 1M | $0 / 1M |
| Cache Write (5m) | $5.00 / 1M | Not applicable |
| Cache Write (1h) | $8.00 / 1M | Not applicable |
| Cache Read | $0.40 / 1M | Not applicable |
| Web Search | $0 / 1M | $0 / 1M |
| Context | ||
| Max context | 1M | N/A |
| Max output | N/A | N/A |
| Capabilities | ||
| Vision | Yes | No |
| Function Calling | Yes | No |
| JSON Mode | Yes | No |
| Streaming | Yes | No |
| Catalogue | ||
| Provider | Anthropic | Fish Audio |
| Category | chat | voice |
| Charge type | Pay As You Go | Pay As You Go |
| Released | — | 2026-07-29 |
| Description | ||
| Summary | Claude Opus 5.5 is Anthropic's flagship model for advanced reasoning, coding, and long-horizon agentic workflows, succeeding Opus 5. It excels at multi-step changes across large codebases, code review and bug detection, financial and scientific analysis, and understanding dense charts, diagrams, and screenshots, with stronger grounding when reporting figures and citing sources. Compared with Opus 5, it completes comparable tasks with fewer steps and lower token usage while providing clearer, more concise progress reporting. With adaptive thinking and configurable effort levels, Opus 5.5 can balance reasoning depth, latency, and cost, making it well suited for both demanding autonomous workflows and latency-sensitive professional tasks. | Fish Audio S2.1 Pro text-to-speech. Billed per UTF-8 byte of input text. |