GPT-5.1 Codex
Codex GPT for repository edits, code review, and practical software agents
- Price per 1M tokens
- $1.25 / $10 input / output · OpenRouter
- Context window
- 400K tokens in · 128K out
- Since the last one
- 59 days after GPT-5-Codex
Since GPT-5-Codex
4 releases in the GPT-5.3 Codex line.
GPT-5-CodexSep 15, 202559dGPT-5.1 CodexNov 13, 202528dGPT-5.2 CodexDec 11, 202556dGPT-5.3 CodexFeb 5, 2026
Released59 days later
Context400Ksame
A newer release is out: GPT-5.3 Codex.
BENCHMARKS
Not in the Epoch Capabilities Index. Epoch benchmarks what it can run, so this is a gap in coverage, not a poor result.
Epoch benchmark boards
Best result on each board it has run. The tick marks the leader.
Terminal Bench58%#17 of 50
OpenAI's past year
24 release days in the past year, about one every 15 days. The next is expected around Nov 8, 2026. Forecasts ↗
NovDecJanFebMarAprMayJunJulAugSepOctNov
Specifications
RELEASE DATENov 13, 2025
WEIGHTSClosed weights
CONTEXT WINDOW400K
MAX OUTPUT128K
REASONINGNot listed
TOOL CALLINGNot listed
INPUTStext, image/jpeg, image/png, image/gif, image/webp
OUTPUTStext
Specifications and prices from Models.dev; availability and limits may differ by provider. Benchmarks from Epoch AI (CC BY 4.0), LiveBench and the other sources named above.