GPT-5.1-Codex-Max
RetiredAn OpenAI model with a 400K-token context window, image input and tool calling. Released on the OpenAI API December 4, 2025, now retired.
Access details: OpenAI API
The model ID to use in API requests.
gpt-5.1-codex-maxUpdated Sep 23, 2026
Capabilities & limits
- Context window
- 400K
- Maximum output
- 128K
- Image input
- Supported
- Tool calling
- Supported
- Structured output
- Supported
Pricing
USD / 1M tokens- Input
- No longer sold
- Output
- No longer sold
No longer sold on the OpenAI API.
Price history
Jul 23, 2026
Input No longer sold per million tokens
Jul 23, 2026
Output No longer sold per million tokens
Technical details
- Parameters
- Not published
- Active parameters
- Not published
- Architecture
- Not published
- Training / knowledge cutoff
- Sep 30, 2024
- Input modalities
- Text, image
- Output modalities
- Text
From OpenAI
Official announcement ↗Release & lifecycle
- First available
- Dec 4, 2025
- deprecated
- As of Sep 13, 2026
- retired
- As of Sep 23, 2026