GPT-5 vs GPT-5.3-Codex
OpenAI GPT-5 | OpenAI GPT-5.3-Codex | |
|---|---|---|
| Overview | ||
| Company | OpenAI | OpenAI |
| Release date | Aug 7 2025 | Feb 5 2026 |
| Access | Proprietary | Proprietary |
| 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. | 21% | 24%Best |
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. | 1394 | 1406Best |
| Timeline | ||
| Release gap | GPT-5 shipped 182 days before GPT-5.3-Codex | |
Which is better: GPT-5 or GPT-5.3-Codex?
GPT-5.3-Codex leads GPT-5 on 2 of the 2 benchmarks they both report (BullshitBench v2, Arena Elo (Code)). GPT-5 shipped 182 days before GPT-5.3-Codex, so benchmark comparisons should account for the intervening progress.
Published specifications for these two models are limited — see each model page for the latest details.
On BullshitBench v2, GPT-5.3-Codex leads at 24% vs GPT-5 at 21%. On Arena Elo (Code), GPT-5.3-Codex leads at 1406 vs GPT-5 at 1394.
Frequently asked questions
GPT-5 was released by OpenAI on Aug 7 2025.
GPT-5.3-Codex was released by OpenAI on Feb 5 2026.
Other comparisons
GPT-5 vs Claude Sonnet 5GPT-5.3-Codex vs Claude Sonnet 5GPT-5 vs Gemini OmniGPT-5.3-Codex vs Gemini OmniGPT-5 vs Muse Spark 1.1GPT-5.3-Codex vs Muse Spark 1.1GPT-5 vs Grok 4.5GPT-5.3-Codex vs Grok 4.5GPT-5 vs DeepSeek-V4-ProGPT-5.3-Codex vs DeepSeek-V4-ProGPT-5 vs Mistral Medium 3.5GPT-5.3-Codex vs Mistral Medium 3.5