Claude Opus 4.8

Published

May 28, 2026

Claude Opus 4.8 is an AI model developed by Anthropic (United States), first published in May 2026. It works in the language domain, on tasks such as language modeling/generation.

Epoch AI has no training-compute estimate for this model.

Access: API access. Its weights are not openly released. Epoch AI rates the confidence of this record as confident.

Full record

Organization: Anthropic
Country of organization: United States
Domain: Language
Task: Language modeling/generation
Model accessibility: API access
Open weights: No
Epoch confidence: Confident

Benchmark results

01

Epoch Capabilities Index

ECI Score

158