Claude Sonnet 5
Everyday Claude agent model for coding, planning, browsing, and general work
ECI STANDING#20 of 266
SCORE156.22153.63–158.63 CI
FRONTIER LAGLaunched 4.8 months behindScores about what GPT-5.3 Codex did in February 2026.
SCORES LIKE THESE MODELSGemini 3.8 FlashGoogle DeepMind · Sep 2026156.54Grok 4.6xAI · Aug 2026156.35Claude Opus 4.7Anthropic · Apr 2026156.34GPT-5.6 LunaOpenAI · Jul 2026156.31
Full Epoch Capabilities Index ranking ↗From the lab
Launch announcement · Jun 30, 2026Released Claude Sonnet 5RELEASE DATEJun 30, 2026
WEIGHTSClosed weights
CONTEXT WINDOW1M
MAX OUTPUT128K
REASONINGYes
TOOL CALLINGYes
INPUTStext, image, pdf
OUTPUTStext
Specifications from Models.dev. Availability and limits may differ by provider. Benchmark scores come from Epoch AI under CC BY 4.0.