About
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...
Related Models
Pricing
Input
$1.25
per 1M tokens
Output
$10.00
per 1M tokens
Blended
$3.44
per 1M tokens
Cheaper than 20% of models. Median price is $0.67/1M tokens.
Cost Calculator
Tokens per day1M
100K100M
Daily
$3.44
Monthly
$103.13
vs. Similar Models
OpenAI: GPT-5.1
$3.440%
OpenAI: GPT-5 Codex
$3.440%
OpenAI: GPT-5
$3.440%
OpenAI: GPT-5.1-Codex
$3.440%
Performance
Context Window
400K
tokens
Larger than 75% of models
Max Output
128K
tokens
32% of context
Context Window Comparison
OpenAI: GPT-5.3-Codex
400KSame
OpenAI: GPT-5.2
400KSame
OpenAI: GPT-5.2-Codex
400KSame