Gemini 2.5 Pro vs GPT-5.1-Codex
Both have similar output pricing, while Gemini 2.5 Pro offers a larger context window. Choose Gemini 2.5 Pro or GPT-5.1-Codex based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | Gemini 2.5 Pro | GPT-5.1-Codex |
|---|---|---|
| Provider | OpenAI | |
| Input / 1M tokens | $1.25 | $1.25 |
| Output / 1M tokens | $10.00 | $10.00 |
| Context window | 1M | 400K |
| Parameters | — | — |
| Open weights | No | No |
| Released | Jun 2025 | Nov 2025 |
| LMArena (Chatbot Arena) Elo score | 1458 | — |
| LMArena WebDev Elo score | 1226 | 1337 |
| LMArena Vision Elo score | 1263 | — |
| LiveBench score | — | 69.3 |
| SWE-bench Verified score | — | 66.0 |
FAQ
Is Gemini 2.5 Pro or GPT-5.1-Codex cheaper?
Gemini 2.5 Pro and GPT-5.1-Codex have comparable output pricing.
Which has the larger context window, Gemini 2.5 Pro or GPT-5.1-Codex?
Gemini 2.5 Pro has the larger context window (1M tokens).
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.