Claude Sonnet 5.5
Lineage
- Company
- Anthropic
- Claude Sonnet family
- 4.655.5the family
- Assistants that offer it
Copilotpaid plan, Microsoft 365 Copilot (USL licence) (copy of an official message ↗)
Perplexitypaid plan, Pro, Max (official page ↗)Claudeselectable, Free and all paid plans, link given for the family (official page ↗)- API price
- 2 $ per million tokens read, 10 $ written (claude.com/pricing, read on 7 November 2026)
Links read on 10/11/2026 on company pages, the press as a fallback; a link given for a family applies only to its latest version.
Rank in each benchmark
- General intelligenceEpoch AI, ECI index166.3163.7 to 169.38th out of 71
- User preferenceLMArena, Elo score147229th out of 68
- Agent tasksEpoch AI, APEX-Agents75.5 %66.3 to 84.73rd out of 52
- Coding tasksEpoch AI, CursorBench55.5 %2nd out of 18
- Code repairEpoch AI, DeepSWEnot measured
Each segment of the bar is worth a tenth of the ranking; the 1st groups the best ranked. Rank among models released in 2026 and measured by the benchmark. Sources: Epoch AI, "Capabilities & benchmarking" (CC BY 4.0); LMArena, text with style control (CC BY 4.0); data as of 10 November 2026.
Success and electricity use of Claude Sonnet 5.5 by effort setting
CursorBench benchmark, 5 settings; electricity use of a task in Wh, estimate, logarithmic scale; data as of 10 November 2026
Line: from setting to setting, at the middle of the rangeBar: the electricity use of a task, from "all read" to "all written" (estimate)
Sources: Epoch AI, CursorBench; electricity: Projet Celsius estimate, AI Impact Database (IA-0011). Licence CC BY 4.0.
Estimation methodology
The effort setting says how much the model reasons before answering: the higher it is, the more tokens it writes, and the more electricity the task needs. Tokens per task are measured by Epoch AI.
Electricity: Projet Celsius estimate. Tokens of the task × electricity ofwriting 1,000 tokens for the size of the model (AI Impact Database, IA-0011), × the data centre overhead (PUE). The scope covers computing on the servers and cooling; it does not cover chip manufacturing, training, the network or the device. CursorBench counts tokens read and written together: the range runs from "all read" to "all written". DeepSWE counts tokens written: the range starts from writing alone.
Assumed model size: medium class, deduced from the output price (claude.com/pricing), assumption. If the model were small, the estimate would be 6 times lower; if it were large, 4 times higher. Benchmark: a quick question to an assistant needs about 0.3 Wh.
Claude Sonnet 5.5 among Anthropic's models, general intelligence
Epoch AI ECI index and its 95% interval, by release date; 12 Anthropic models released in 2026 and measured by the ECI index
Dot: the index measured, at the release dateLine: the 95% intervalClaude Sonnet 5.53 names in the "Table" tab
Source: Epoch AI, "Capabilities & benchmarking", ECI index. CC BY 4.0 licence.
On a coding task, Claude Sonnet 5.5 needs 63 to 190 Wh at its most demanding setting, as much as about 210 to 630 quick questions to an assistant (about 0.3 Wh each).
Continue in the ranking
The full ranking →CompanyAnthropic12models measuredIts assistant, its models, its governance and the electricity of its data centres.The entry →ModelAnthropicClaude Sonnet 532ndout of 71 on general intelligenceThe previous version of Claude Sonnet.The entry →AssistantClaude74out of 100, 1st out of 10One of the 3 assistants in the ranking that offer Claude Sonnet 5.5.The entry →The hub newsletter
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