Chess with an engine
loads medium
Tech. quality98
UX83
Time11 min 03 s
Cost≈ $1.42
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Claude Sonnet 5.5
Loads without errors4/5#12 of 26
Tech. quality95/100#9 of 26
UX85/100#13 of 26
Total cost≈ $8.08
Average time17 min 30 s#24 of 26
Total tokens877,582
API price: $2 / $10 per 1M input / output tokens · as of 06/10/2026 source ↗
What is Claude Sonnet 5.5 good for?
The middle model of the Claude family, which Anthropic describes as the best combination of speed and intelligence.
Description based on the maker · source ↗
- Maker
- Anthropic
- Released
- 28/09/2026
- Context window
- 1M tokens
- Model weights
- closed, the model is available through the API only
- Reasoning levels
- low medium high xhigh max
How did Claude Sonnet 5.5 do in the AI Lab tests?
- 4 of 5 outputs load without errors; 1 more ran after one fix by the same model.
- Its best technical result was on the “GTA-style game” prompt (100/100).
- Did not work (original output): Monitor test.
- It implemented the chess rules flawlessly – passing the objective perft test on all 6 positions.
- Average time per prompt 17 min 30 s#24 of 26
- Average cost per prompt ≈ $1.62#25 of 26
- Technical quality 95/100#9 of 26
- Automatic UX rating 85/100#13 of 26
Outputs
All outputs of Claude Sonnet 5.5 on the 5 prompts every other model got as well.
New York & Central Park map
loads medium
Tech. quality98
UX80
Time37 min 03 s
Cost≈ $2.11
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GTA-style game
loads medium
Tech. quality100
UX100
Time17 min 03 s
Cost≈ $1.81
Compare →
Solar System
loads medium
Tech. quality95
UX84
Time15 min 14 s
Cost≈ $1.70
Compare →
Monitor test
broken medium fixed version →
Tech. quality83
UX79
Time7 min 05 s
Cost≈ $1.04
Compare →
Cost = tokens priced with the API price list valid on the date shown next to the cost (prices change). ≈ = estimate (only the total token count is known), no ≈ = exact from input / output tokens. “Loads” = the page opens without errors; technical quality also checks behaviour during use – judge the quality in the viewer.