Back to all models
openai
openaiOpenAI: 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...
openai/gpt-5.1-codex-max
Context Size
400K
Input Price
7,687.5 Ks/M
Output Price
61,500 Ks/M
Architecture
Text
Image
Supported Parameters
include_reasoningmax_completion_tokensmax_tokensreasoningresponse_formatseedstructured_outputstool_choicetools
Details
TokenizerGPT
Max Completion128,000 tokens
Provider Context400K tokens
ModeratedYes