ModelBeat
Models/GPT-5.1-Codex-Max
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OpenAI: GPT-5.1-Codex-Max

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.

Context
400K
Input
$1.25 / 1M
Output
$10 / 1M
Released
Nov 19, 2025
Modalities
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Benchmarks

Scores on standardized evaluations. Higher is better — and rank shows where GPT-5.1-Codex-Max lands among all models tracked on Model Beat.

62.0
Intelligence Index
Epoch AI
62nd percentile of tracked models
70.0
Coding Index
Epoch AI
70th percentile of tracked models
54.0
Agentic Index
Epoch AI
54th percentile of tracked models

Agentic & Tools

2 evals
METR task horizon2.7 h

Autonomous task length

Terminal-Bench60.4%

Command-line agentic tasks

In the news

2

Model & benchmark data from Epoch AI (CC BY); pricing, specs & descriptions from OpenRouter.