Gemini 2.5 Pro is Google's reasoning model for problems that do not fit anywhere else. The number that defines it is the context window: 1,048,576 tokens, roughly 1,500 pages held in working memory at once. Hand it an entire repository, a full deposition, or a year of meeting transcripts, then ask a question whose answer depends on all of it.
That capacity is the reason to choose this model. It is also the reason to think first.
What it accepts
Gemini 2.5 Pro is natively multimodal on the way in. It reads:
- Text — documents, source code, transcripts
- Images — screenshots, diagrams, scanned pages
- Audio — calls, interviews, lectures
- Video — recorded sessions and screen captures
- PDF — parsed directly, with no separate extraction step
Output is text only. If half your job is generating images or speech, this model does not do that half.
Where it earns its place
Reasoning is on by default, and that changes what the model is good at. It works through a problem in steps instead of answering from the first plausible pattern. The practical effect shows up in work where being wrong is expensive: reconciling documents that contradict each other, tracing a bug across files that never mention each other, planning a migration where order matters.
Function calling and JSON mode are both supported, so it fits into agent loops and structured pipelines without post-processing hacks to force the shape of a response.
Where it does not
Deliberation costs time. On high-volume, low-stakes calls — classification, tagging, short replies — you are paying latency for thinking the task never needed. Gemini 2.5 Flash carries the same million-token window and returns faster, which is usually the better trade at volume.
The 65,536-token output ceiling is generous, not infinite. Book-length generation still has to be chunked and stitched.
Specifications
| Field |
Value |
| Provider |
Google |
| Context window |
1,048,576 tokens |
| Maximum output |
65,536 tokens |
| Input |
text, image, audio, video, PDF |
| Output |
text |
| Reasoning |
Yes |
| Function calling |
Yes |
| JSON mode |
Yes |
| Released |
16 June 2025 |
Pricing, quotas and regional availability change frequently, so we deliberately do not reproduce them here. Confirm current figures against your own account before you commit to a budget.
Compare it against the rest of the AI model directory, or read how it differs from the faster sibling in Gemini 2.5 Flash.