Claude Opus 4.1
Flagship Claude model for deep reasoning, coding, and long-horizon agents
ECI STANDING#83 of 266
SCORE144.11142.06–145.99 CI
FRONTIER LAGLaunched 4.2 months behindScores about what Gemini 2.5 Pro (Mar 2025) did in March 2025.
SCORES LIKE THESE MODELS
Full Epoch Capabilities Index ranking ↗Grok 4 FastxAI · Sep 2025144.21
Gemini 2.5 Pro (Mar 2025)Google DeepMind · Mar 2025144.16
Qwen 3.5 Flash (hosted 35B-A3B)Alibaba · Feb 2026144.0
Qwen3-235B-A22B-Thinking (Jul 2025)Alibaba · Jul 2025143.88
From the lab
Launch announcement · Aug 5, 2025Released Claude Opus 4.1RELEASE DATEAug 5, 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.