GPT-5 vs GPT-5.1-Codex
Both have similar output pricing. Choose GPT-5 or GPT-5.1-Codex based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | GPT-5 | GPT-5.1-Codex |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Input / 1M tokens | $1.25 | $1.25 |
| Output / 1M tokens | $10.00 | $10.00 |
| Context window | 400K | 400K |
| Parameters | — | — |
| Open weights | No | No |
| Released | Aug 2025 | Nov 2025 |
| SWE-bench Verified score | 75.6 | 66.0 |
| Aider Polyglot score | 88.0 | — |
| LMArena (Chatbot Arena) Elo score | 1406 | — |
| LMArena WebDev Elo score | 1417 | 1337 |
| LMArena Vision Elo score | 1208 | — |
| GPQA Diamond score | 86.2 | — |
| FrontierMath score | 32.4 | — |
| Epoch Capabilities Index score | 150 | — |
| LiveBench score | — | 69.3 |
FAQ
Is GPT-5 or GPT-5.1-Codex cheaper?
GPT-5 and GPT-5.1-Codex have comparable output pricing.
Which has the larger context window, GPT-5 or GPT-5.1-Codex?
Both models offer a similar context window.
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.