Gemini 3.1 Pro Preview vs Gemini 3 Flash Preview: API cost
Standard, cached and batch API prices for Gemini 3.1 Pro Preview (Google) and Gemini 3 Flash Preview (Google), and what each costs for your usage.
Gemini 3 Flash Preview is cheaper than Gemini 3.1 Pro Preview at standard rates, with 4× cheaper input and 4× cheaper output.
- Input $60.00
- Cached input $6.00
- Output $108.00
- Input $15.00
- Cached input $1.50
- Output $27.00
Show as a table
| Output tokens | Gemini 3.1 Pro Preview | Gemini 3 Flash Preview |
|---|---|---|
| 0 | $2.00 | $0.5 |
| 250 | $5.00 | $1.25 |
| 500 | $8.00 | $2.00 |
| 750 | $11.00 | $2.75 |
| 1,000 | $14.00 | $3.50 |
| Token type | Gemini 3.1 Pro Preview | Gemini 3 Flash Preview | |
|---|---|---|---|
| Input | $2 | $0.50 | Gemini 3 Flash Preview is 4× cheaper |
| Cached input | $0.20 | $0.05 | Gemini 3 Flash Preview is 4× cheaper |
| Output | $12 | $3 | Gemini 3 Flash Preview is 4× cheaper |
| Batch input | $1 | $0.25 | Gemini 3 Flash Preview is 4× cheaper |
| Batch cached input | $0.20 | $0.05 | Gemini 3 Flash Preview is 4× cheaper |
| Batch output | $6 | $1.50 | Gemini 3 Flash Preview is 4× cheaper |
Gemini 3.1 Pro Preview: Prompts over 200K tokens are billed at a higher rate.
Gemini 3 Flash Preview: Audio input costs more.
| Workload | Gemini 3.1 Pro Preview | Gemini 3 Flash Preview |
|---|---|---|
Support chatbot 2,000 in / 300 out tokens,
1,000 requests a day, 50% cached | $174.00 | $43.50 |
Document summaries 10,000 in / 800 out tokens,
200 requests a day | $177.60 | $44.40 |
Tagging / classifying 400 in / 20 out tokens,
20,000 requests a day | $624.00 | $156.00 |
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Or see Gemini 3.1 Pro Preview pricing, Gemini 3 Flash Preview pricing, or compare any two models.
FAQ
Frequently asked questions
Is Gemini 3.1 Pro Preview cheaper than Gemini 3 Flash Preview?
Gemini 3 Flash Preview is cheaper than Gemini 3.1 Pro Preview at standard rates, with 4× cheaper input and 4× cheaper output. Based on standard API rates last checked on 30 Sept 2026.
How much do Gemini 3.1 Pro Preview and Gemini 3 Flash Preview cost per million tokens?
Gemini 3.1 Pro Preview: $2 per million input tokens and $12 per million output tokens. Gemini 3 Flash Preview: $0.50 input and $3 output. These are standard rates in USD, before tax, from each provider’s own pricing page.
Which is cheaper with the Batch API?
Gemini 3.1 Pro Preview’s batch rates are $1 input and $6 output per million tokens (50% off); Gemini 3 Flash Preview’s batch rates are $0.25 input and $1.50 output per million tokens (50% off).
Does prompt caching change the comparison?
Gemini 3.1 Pro Preview charges $0.20 per million cached input tokens, against $2 for normal input; Gemini 3 Flash Preview charges $0.05 per million cached input tokens, against $0.50 for normal input. Cache write and storage charges are extra and aren’t included here.