GPT 5.1 Codex Max is a retired AI model from OpenAI.

GPT 5.1 Codex Max has a recorded input context length of 400,000 tokens.

The lowest base rates currently recorded across providers for GPT 5.1 Codex Max are Input Text Tokens at $1.25 per 1M tokens; Output Text Tokens at $10.00 per 1M tokens; and Cache Read Tokens at $0.13 per 1M tokens. The pricing section shows every recorded provider, pricing plan, meter, and condition.

GPT 5.1 Codex Max is available through the Phaseo API, with 1 active provider currently recorded. The providers section shows the routes and availability currently recorded by Phaseo.

Yes. At least one active provider route for GPT 5.1 Codex Max currently advertises tool calling support. Provider support can vary, so requests are routed only to compatible routes.

Yes. At least one active provider route for GPT 5.1 Codex Max currently advertises structured outputs support. Provider support can vary, so requests are routed only to compatible routes.

Phaseo records GPT 5 1 Codex as the previous model. View the model family for the complete release history.

GPT 5.1 Codex Max accepts image and text inputs. It produces text output.

GPT 5.1 Codex Max was released on 19 Nov 2025.