AI Model Release Tracker

GPT-5.2-Codex

Released

GPT-5.2-Codex is an AI model released by OpenAI on Thursday, Dec 18 2025, 7 days after GPT-5.2. It has a 400k token context windowHow much information the model can work with in one request, measured in tokens — pieces of words or other data. This includes your question, attachments, conversation and reply. Limits can vary by model variant and provider.. Benchmark results (shown below) cover BullshitBench v2, and Next.js Evals.

Benchmarks

Coding

Next.js EvalsNext.js coding — Vercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better.via Next.js Evals
46%
#33 of 36

Robustness

BullshitBench v2Nonsense detection — Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better.via BullshitBench
45%
#48 of 100

Compare GPT-5.2-Codex with

GPT-5.2-Codex

Suggested comparisons

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About

OpenAI introduced GPT-5.2-Codex on December 18, 2025 for software engineering in large repositories. OpenAI highlighted context compaction for long sessions, tool use and work in native Windows environments.

The first release reached paid ChatGPT users through Codex. OpenAI added Responses API access on January 14, 2026.

Frequently asked questions

GPT-5.2-Codex was released by OpenAI on Thursday, Dec 18 2025.

All OpenAI releases

55 tracked

2022

1 release
GPT-3.5
Nov 30 2022