Claude Opus 4
Flagship Claude model for deep reasoning, coding, and long-horizon agents
ECI STANDING#90 of 266
SCORE142.68140.74–144.27 CI
FRONTIER LAGLaunched 1.7 months behindScores about what Gemini 2.5 Pro (Mar 2025) did in March 2025.
SCORES LIKE THESE MODELSGemma 4 31B ITGoogle DeepMind · Apr 2026142.66Qwen3.5-35B-A3BAlibaba · Feb 2026142.53GPT-5.5 InstantOpenAI · May 2026142.5
Full Epoch Capabilities Index ranking ↗Gemini 2.5 Pro (May 2025)Google DeepMind · May 2025142.47
From the lab
Launch announcement · May 22, 2025Released Claude Opus 4 and Claude Sonnet 4RELEASE DATEMay 22, 2025
WEIGHTSClosed weights
CONTEXT WINDOW200K
MAX OUTPUT32K
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.