Compare / Models
Gemini 2.5 Pro vs GPT-5.5
Price, context window and capabilities side by side — read from the same catalog that meters your calls, not from a press release.
Gemini 2.5 Pro is 4.0x cheaper on input. Gemini 2.5 Pro is 3.0x cheaper on output. Gemini 2.5 Pro holds 1M tokens against 256K.
At a glance
Side by side
Google's stable Pro tier, the non-preview reasoning model.
Retired. Use Gemini 3.1 Pro (preview) instead — same endpoint, same key.
Specifications
Every difference we can measure
| Gemini 2.5 Pro | GPT-5.5 | |
|---|---|---|
| Input price | $1.25/M | $5/M |
| Output price | $10/M | $30/M |
| Context window | 1M tokens | 256K tokens |
| Vision | Yes | Yes |
| Tool calling | Yes | Yes |
| Prompt caching | Yes | No |
| Long context | Yes | No |
A row appears only when we hold the fact for both models. Anything the provider has not published is left out rather than guessed, so an empty row is missing data and never a zero.
Keep looking
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FAQ
Frequently asked questions
What is the difference between Gemini 2.5 Pro and GPT-5.5?
Gemini 2.5 Pro is 4.0x cheaper on input. Gemini 2.5 Pro is 3.0x cheaper on output. Gemini 2.5 Pro holds 1M tokens against 256K. Only Gemini 2.5 Pro declares prompt caching. Only Gemini 2.5 Pro declares long context. Both run on the same endpoint and the same key here, so trying each is a one-line change to the model id.
Which is cheaper, Gemini 2.5 Pro or GPT-5.5?
Gemini 2.5 Pro is, on input tokens. Output usually dominates the bill on generative work, so check the output row above against your own ratio of prompt to completion before deciding.
Can I switch between Gemini 2.5 Pro and GPT-5.5 without changing my code?
Yes. Both are OpenAI-compatible through one CompanyFabric key, so switching is the model string and nothing else — no second SDK, no second contract, one prepaid balance across both.
Do I have to choose?
No. Send companyfabric/auto and we route each request to the cheapest model that can serve it, which is how most people use both without deciding in advance.
One key. Every model. Exact prices.
Run Gemini 2.5 Pro and GPT-5.5 on the same key and compare them on your own prompts. Free starter credits included, no subscription required.