GPT-5.1 Codex
Codex GPT for repository edits, code review, and practical software agents
BENCHMARKS
Not in the Epoch Capabilities Index. Epoch benchmarks what it can run, so this is a gap in coverage, not a poor result.
RELEASE DATENov 13, 2025
WEIGHTSClosed weights
CONTEXT WINDOW400K
MAX OUTPUT128K
REASONINGYes
TOOL CALLINGYes
INPUTStext, image
OUTPUTStext
Specifications from Models.dev. Availability and limits may differ by provider. Benchmark scores come from Epoch AI under CC BY 4.0.