GPT-5.1-Codex-Max
GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks. It is based on an updated version of the 5.1 reasoning stack and trained on agentic...
The figures
- Made by
- OpenAI
- Model ID
- openai/gpt-5.1-codex-max
- Input
- $1.25 per million tokens
- Output
- $10 per million tokens
- Context window
- 400K tokens
- Longest answer
- 128K tokens
- Takes in
- text, image
- Gives back
- text
- Reasoning
- Yes
- Tool calling
- Yes
- Reads images
- Yes
- Open weights
- No
- Released
- 4 Dec 2025
Read on 3 Oct 2026.