GPT-5.1-Codex

Published

Nov 12, 2025

GPT-5.1-Codex is an AI model developed by OpenAI (United States), first published in November 2025. It works in the language domain, on tasks such as language modeling/generation.

Epoch AI has no training-compute estimate for this model.

Access: API access. Its weights are not openly released.

Full record

Organization: OpenAI
Country of organization: United States
Domain: Language
Task: Language modeling/generation
Model accessibility: API access
Open weights: No

Benchmark results

01	WebDev Arena	Arena Score	1331
02	ALE Bench	Performance	1244.9
03	Terminal-Bench	Accuracy mean	0.58
04	Apex Agents	Pass@1 score	0.21