Claude Sonnet 5.5
Claude Sonnet 5.5 is Anthropic's latest medium-tier model and the successor to Sonnet 5. It scores 55.5% on CursorBench at max effort, second only to Opus 5.5, and keeps Sonnet 5's per-token price. Add it to the model picker from Cursor Settings > Models.
Strengths
- Frontier-level CursorBench results at Sonnet pricing. It sits on the same cost-performance frontier as Opus 5.5.
- Scales with effort. Its score climbs from 35.8% at low effort to 55.5% at max, so you can trade tokens for quality on harder tasks.
- Supports thinking mode and context windows up to 1M tokens.
Limitations
- For peak quality on the hardest tasks, Opus 5.5 remains the stronger choice.
- Higher effort levels use many more tokens. On CursorBench, max effort costs about 6x more per task than the default high effort.
Tools
Sonnet 5.5 has access to all agent tools when used with Cursor including:
Find files by name, read directory structures, and grep for patterns.
Generate search queries and fetch results from the web.
Read file contents, including images for vision-capable models.
Suggest edits and apply them automatically.
Execute terminal commands and monitor output.
Control a browser to take screenshots, test applications, and verify visual changes. See the Browser documentation.
Generate images from text descriptions or reference images.
Ask clarifying questions while continuing to work in the background.
Retrieve rules based on type and description.
Learn more about how tools work and tool calling fundamentals.
Pricing
Cursor plans include two usage pools. Sonnet 5.5 draws from the third-party Other Models pool, which charges at the rates below. All prices are per million tokens.
| Name | ||||
|---|---|---|---|---|
| $2 | $2.5 | $0.2 | $10 |
Sonnet 5.5 bills at $2 per million input tokens and $10 per million output tokens, the same as Sonnet 5. Prompt-cache reads are $0.20 per million tokens.
Global endpoints use the rates above. US-only endpoints are priced 10% higher, at $2.20/M input and $11/M output tokens. See Privacy and Data Governance for data residency details.
All Sonnet 5.5 prompts bill at the base per-token rates in the table above, including when context goes above 200k. There is no separate long-context multiplier for Sonnet 5.5.
A thinking variant is available for deeper reasoning.