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 is the cheapest — 25% less than the priciest here ($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 |
| Quality score | 93/100 | 72/100 |
| Tier | Flagship | Flash |
| Provider |
Projected monthly cost
| Requests / mo | Gemini 3.1 Pro | Gemini 3.5 Flash |
|---|---|---|
| 1,000 | $7.20 | $5.40 |
| 10,000 | $72.00 | $54.00 |
| 100,000 | $720.00 | $540.00 |
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.