Anthropic's Claude Sonnet 5.5 is the second model in the Claude 5.5 family. On Terminal-Bench 4.0, an agentic coding test, it scores 70.6%, up from 10.3% for Sonnet 5 and ahead of Opus 5.5 at 66.4%.
Here's the score table, the price, how to switch, and the catches.
The score table
| Benchmark | Sonnet 5.5 | Sonnet 5 | Opus 5.5 |
|---|---|---|---|
| Terminal-Bench 4.0 | 70.6% | 10.3% | 66.4% (Xhigh effort) |
| CursorBench 4.0 | 55.5% | 34.1% | 57.8% |
| OSWorld 2.1 (partial) | 80.1% | 57.0% | 81.8% |
It runs 30% or more faster than Sonnet 5. Opus 5.5 still wins on CursorBench and OSWorld.
What it costs
| Per million tokens | Sonnet 5.5 | Opus 5.5 |
|---|---|---|
| Input | $2 | $4 |
| Output | $10 | $20 |
| Cache reads | $0.20 |
The base price matches Sonnet 5.
Free, for your email
Get the full setup steps + the copy-paste setup prompt
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Unlocks: Step 1: switch · The catches · Test it on your own code · Sources
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