OpenAI logo

OpenAI

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 workflows spanning software engineering, mathematics, and research. GPT-5.1-Codex-Max delivers faster performance, improved reasoning, and higher token efficiency across the development lifecycle.

Input / 1M tokens
$1.25
Output / 1M tokens
$10.00
Context window
400K tokens
Provider
OpenAI
Cached input / 1M
$0.125

Performance

Median streaming throughput and first-token latency measured by Artificial Analysis.

Output tokens / sec
Time to first token