OpenAI
GPT-5.3-Codex
GPT-5.3-Codex is an AI model released by OpenAI on Thursday, Feb 5 2026, 56 days after GPT-5.2. Benchmark results (shown below) cover BullshitBench v2, Next.js Evals, and Arena Elo (Code).
Benchmarks
Nonsense detection
BullshitBench v2Given 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.
24%
Next.js coding
Next.js EvalsVercel'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.
83%
Community preference (code)
Arena Elo (Code)Like the text arena, but people vote on which AI writes better code. The votes become a chess-style Elo rating on arena.ai. Higher is better.
1406