Claude 2.1 vs GPT-5-Codex
Anthropic Claude 2.1 | OpenAI GPT-5-Codex | |
|---|---|---|
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | Nov 21 2023 | Sep 15 2025 |
| 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. | — | 39% |
| Timeline | ||
| Release gap | Claude 2.1 shipped 664 days before GPT-5-Codex | |
Which is better: Claude 2.1 or GPT-5-Codex?
Claude 2.1 and GPT-5-Codex don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude 2.1 shipped 664 days before GPT-5-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 2.1 and GPT-5-Codex don't publish scores on any of the same benchmarks.
Frequently asked questions
Claude 2.1 was released by Anthropic on Nov 21 2023.
GPT-5-Codex was released by OpenAI on Sep 15 2025.
Other comparisons
Claude 2.1 vs Gemini OmniGPT-5-Codex vs Gemini OmniClaude 2.1 vs Muse Spark 1.1GPT-5-Codex vs Muse Spark 1.1Claude 2.1 vs Grok 4.5GPT-5-Codex vs Grok 4.5Claude 2.1 vs DeepSeek-V4-ProGPT-5-Codex vs DeepSeek-V4-ProClaude 2.1 vs Mistral Medium 3.5GPT-5-Codex vs Mistral Medium 3.5Claude 2.1 vs Kimi K2.7 CodeGPT-5-Codex vs Kimi K2.7 Code