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Modelreleased on 28 May 2026

Claude Opus 4.8

20thout of 71General intelligence, ECI index 159.9 (157.8 to 162.3)
Agent tasks32nd out of 5248.9% completed
Coding tasksnot measuredCursorBench
Electricity use of a tasknot estimatedmodel size unknown

Lineage

Company
Anthropic
Claude Opus family
4.64.74.855.5the 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 index159.9157.8 to 162.320th out of 71
  • User preferenceLMArena, Elo score148223rd out of 68
  • Agent tasksEpoch AI, APEX-Agents48.9 %38.1 to 59.732nd out of 52
  • Code repairEpoch AI, DeepSWE59.0 %14th 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 estimated40.8 %28,923
mediumnot estimated48.7 %41,313
highnot estimated51.8 %50,064
xhighnot estimated54.4 %86,089
maxnot estimated59.0 %135,032
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 Opus 4.8 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 Opus 4.8Claude Fable 5.2Claude Opus 5.5Claude Fable 5.1Claude Sonnet 5.5Claude Opus 5Claude Fable 5Claude Haiku 5.5Claude Opus 4.7

Dot: the index measured, at the release dateLine: the 95% intervalClaude Opus 4.83 names in the "Table" tab

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

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