Claude Opus 5.5 vs Claude Sonnet 5.5
API pricing, context, and independently measured performance, side by side. Claude Sonnet 5.5 starts 50% cheaper on input than Claude Opus 5.5 at list prices.
Claude Opus 5.5
Anthropic · released Sep 22, 2026
Best input$4.00 / MTok
Best output$20.00 / MTok
Context1M
Providers13
Fastest measured3.7s° TTFT · 216 tok/s
VisionToolsReasoningStructured outputPrompt caching
Claude Sonnet 5.5
Anthropic · released Sep 28, 2026
Best input$2.00 / MTok
Best output$10.00 / MTok
Context1M
Providers8
Fastest measured1.2s° TTFT · 206 tok/s
VisionToolsReasoningStructured outputPrompt caching
Cheapest providers, measuredUSD / MTOK
| MODEL | PROVIDER | INPUT | OUTPUT | TTFT | TPS | SMOKE |
|---|---|---|---|---|---|---|
| Claude Opus 5.5 | $4.00 | $20.00 | — | — | — | |
| Claude Opus 5.5 | $4.00 | $20.00 | 3.7s° | 216° tok/s | — | |
| Claude Opus 5.5 | $4.00 | $20.00 | 3.9s° | 164° tok/s | — | |
| Claude Sonnet 5.5 | $2.00 | $10.00 | 1.2s° | 206° tok/s | — | |
| Claude Sonnet 5.5 | $2.00 | $10.00 | — | — | — | |
| Claude Sonnet 5.5 | $2.00 | $10.00 | — | — | — |
TTFT/TPS: ModelIndex-measured medians (P50, trailing 21d) · chat10k profile (~10K in / 200 out) · ° = measured via OpenRouter routing (adds a hop) · SMOKE: of 5 programmatic capability probes passed · methodology v1.1 — full details on each model page