GPT-5.1 Codex
OpenAI's coding-tuned GPT-5 variant.
OpenAICodexCtx 400k
OpenAI
Codex
Released 2026-01GPT-5.1 Codex
OpenAI's coding-tuned GPT-5 variant.
Codex 5.1 is the coding-specialized model line, tuned for repo-scale edits, diffs, and passing test suites.
Codex Published 2026-01#openai#llm#review
Context
400k
Input
$1.50/M
Output
$12/M
Released
2026-01
Modalities
Text
Strengths
- Code-specialized
- Deep repo reasoning
- Test-driven output
Best for
Coding agents
Repo refactors
GPT-5.1 Codex FAQ
Sources & further reading
Cite this page
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APA
Build on Vibe Editorial (2026). GPT-5.1 Codex OpenAI's coding-tuned GPT-5 variant.. Build on Vibe. Retrieved from https://buildonvibe.site/models/gpt-5-1-codex
BibTeX
@misc{bov-models-gpt-5-1-codex,
title = {GPT-5.1 Codex OpenAI's coding-tuned GPT-5 variant.},
author = {Build on Vibe Editorial},
year = {2026},
url = {https://buildonvibe.site/models/gpt-5-1-codex},
note = {Build on Vibe}
}