Gemini 3.1 Pro vs Gemini 3.5 Flash
List-price comparison · Gemini 3.1 Pro details · Gemini 3.5 Flash details
For a typical workload (100,000 requests / mo), Gemini 3.5 Flash costs 25% less — $540.00/mo vs $720.00/mo.
| Gemini 3.1 Pro | Gemini 3.5 Flash | |
|---|---|---|
| Input / 1M tokens | $2.00 | $1.50 |
| Output / 1M tokens | $12.00 | $9.00 |
| Typical request (1,200 in + 400 out) | $0.0072 | $0.0054 |
| Context window | 1,048,576 tokens | 1,048,576 tokens |
| Max output | 65,536 tokens | 65,536 tokens |
| Tier | Flagship | Flash |
| Provider |
Projected monthly cost
Rows open both models in the calculator — adjust volume and token counts there.
Gemini 3.1 Pro
Native audio, video, and document understanding with a ~1M token context window — strong fit for multi-modal RAG and large-document analysis.
Output token cost is steep relative to input, and the largest context windows can be slow to fill — chunk large documents where possible.
Gemini 3.5 Flash
Fast, cheap multi-modal model with the same 1M-token context as the Pro tier — good for high-volume document Q&A and image/audio triage.
Reasoning quality trails the Pro tier on complex, multi-step tasks; best used where speed and context size matter more than depth.
More comparisons
Vendor list rates · per-request examples assume 1,200 input + 400 output tokens.