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Modelreleased on 9 June 2026

Claude Fable 5

10thout of 71General intelligence, ECI index 164.3 (161.8 to 167.0)
Agent tasks15th out of 5263.6% completed
Coding tasksnot measuredCursorBench
Electricity use of a tasknot estimatedmodel size unknown

Lineage

Company
Anthropic
Claude Fable family
55.15.2the family
Assistants that offer it
No assistant in the ranking names it on a page we have read.
API price
not recorded

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 index164.3161.8 to 167.010th out of 71
  • User preferenceLMArena, Elo score15045th out of 68
  • Agent tasksEpoch AI, APEX-Agents63.6 %53.2 to 74.015th out of 52
  • Code repairEpoch AI, DeepSWE69.9 %5th out of 26
  • Coding tasksEpoch AI, CursorBenchnot 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.

Effort settings

SettingElectricity use of a taskTasks completedTokens per task
DeepSWE, code repair
lownot estimated59.6 %25,243
mediumnot estimated65.4 %40,201
highnot estimated68.6 %57,287
xhighnot estimated69.9 %80,352
maxnot estimated69.7 %118,593
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.

Model size unknown: electricity use is not estimated. Benchmark: a quick question to an assistant needs about 0.3 Wh.

Claude Fable 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

FebAprJunAugOct150160170180General intelligence index (ECI)Claude Fable 5Claude Fable 5.2Claude Opus 5.5Claude Fable 5.1Claude Sonnet 5.5Claude Opus 5Claude Haiku 5.5Claude Opus 4.8Claude Opus 4.7

Dot: the index measured, at the release dateLine: the 95% intervalClaude Fable 53 names in the "Table" tab

Source: Epoch AI, "Capabilities & benchmarking", ECI index. CC BY 4.0 licence.

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