Comparison
Gemini 2.5 Pro vs GPT-5.1
How Gemini 2.5 Pro and GPT-5.1 compare on the numbers that decide the call - and how to switch between them without touching your code.
| Spec | Gemini 2.5 Pro | GPT-5.1 |
|---|---|---|
| Input price / 1Mlower is cheaper | $1.25 | $1.25 |
| Output price / 1Mlower is cheaper | $10 | $10 |
| Context windowbigger fits more | 1.048576M | 400K |
| Typical speedfaster median | 1.1s | 1.4s |
| Quality score | 92/100 | 95/100 |
| Provider | OpenAI |
Which should you pick?
- Gemini 2.5 Pro takes a larger context window (1.048576M tokens).
- Gemini 2.5 Pro is usually the faster to answer.
- GPT-5.1 scores higher on the composite quality benchmark.
You do not have to choose permanently. Name one as your first choice and let Final Router fall back to the other when a provider fails - the request still gets answered, and the log shows which model replied.
Common questions
- Is Gemini 2.5 Pro or GPT-5.1 cheaper?
- Their input token prices are the same ($1.25 per 1M). Compare output: $10 vs $10.
- Can I switch between Gemini 2.5 Pro and GPT-5.1 without changing my code?
- Yes. Both are called through the same OpenAI-compatible endpoint - change only the model id ("google/gemini-2.5-pro" or "openai/gpt-5.1"), or let a routing policy fall back from one to the other automatically.