CODE & AGENTS · OpenAI
GPT-5.1-Codex-Max
GPT-5.1-Codex-Max is a reasoning, tool-using model from OpenAI in the GPT family, living in The Cedar Forest (code & agents). It reads text and images and writes text, with a 400K-token context window and up to 128K tokens of output. On OpenRouter it costs $1.25 per million input tokens and $10.0 per million output tokens.
See GPT-5.1-Codex-Max in 3DOpen in the WorktableView on OpenRouter
Specifications
- Provider
- OpenAI
- Family
- GPT
- Province
- The Cedar Forest
- Context window
- 400K tokens
- Maximum output
- 128K tokens
- Input / 1M tokens
- $1.25
- Output / 1M tokens
- $10.0
- Accepts
- text, images
- Produces
- text
- Reasoning
- Yes
- Tool use
- Yes
- Added to OpenRouter
- 2025-12-04
- Model ID
openai/gpt-5.1-codex-max- Price history
- —All recorded prices
From the 2026-10-24 catalog snapshot. Prices are US dollars per million tokens.
More GPT models
- GPT-5.3-Codex400K · $1.75 / $14.0
- GPT-5.2-Codex400K · $1.75 / $14.0
- GPT-5.1-Codex400K · $1.25 / $10.0
- GPT-5.1-Codex-Mini400K · $0.250 / $2.00