Claude 1 vs GPT-5.3-Codex
Anthropic Claude 1 | OpenAI GPT-5.3-Codex | |
|---|---|---|
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | Mar 14 2023 | 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. | — | 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 |
| Timeline | ||
| Release gap | Claude 1 shipped 1059 days before GPT-5.3-Codex | |
Which is better: Claude 1 or GPT-5.3-Codex?
Claude 1 and GPT-5.3-Codex don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude 1 shipped 1059 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.
Direct benchmark comparisons are unavailable — Claude 1 and GPT-5.3-Codex don't publish scores on any of the same benchmarks.
Frequently asked questions
Claude 1 was released by Anthropic on Mar 14 2023.
GPT-5.3-Codex was released by OpenAI on Feb 5 2026.
Other comparisons
Claude 1 vs Gemini OmniGPT-5.3-Codex vs Gemini OmniClaude 1 vs Muse Spark 1.1GPT-5.3-Codex vs Muse Spark 1.1Claude 1 vs Grok 4.5GPT-5.3-Codex vs Grok 4.5Claude 1 vs DeepSeek-V4-ProGPT-5.3-Codex vs DeepSeek-V4-ProClaude 1 vs Mistral Medium 3.5GPT-5.3-Codex vs Mistral Medium 3.5Claude 1 vs Kimi K2.7 CodeGPT-5.3-Codex vs Kimi K2.7 Code