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Gemini 3.1 Flash-Lite vs Gemini 3.1 Pro Preview: API cost

Standard, cached and batch API prices for Gemini 3.1 Flash-Lite (Google) and Gemini 3.1 Pro Preview (Google), and what each costs for your usage.

Prices last checked: how

Gemini 3.1 Flash-Lite is cheaper than Gemini 3.1 Pro Preview at standard rates, with 8× cheaper input and 8× cheaper output.

Your usage
Gemini 3.1 Flash-Lite / month $21.75 $0.00072 per request
  • Input $7.50
  • Cached input $0.75
  • Output $13.50
Gemini 3.1 Pro Preview / month $174.00 $0.0058 per request
  • Input $60.00
  • Cached input $6.00
  • Output $108.00
Gemini 3.1 Flash-Lite is cheaper for this usage by $152.25 a month (88% less).

How cost changes with reply length

  • Gemini 3.1 Flash-Lite
  • Gemini 3.1 Pro Preview
$0$5$10$1502004006008001,000Output tokens per 1,000 input tokensGemini 3.1 Flash-…Gemini 3.1 Pro Pr…
Cost of 1,000 requests with 1,000 input tokens each, at standard rates without caching. Hover or use the arrow keys to read values.
Show as a table
Output tokensGemini 3.1 Flash-LiteGemini 3.1 Pro Preview
0$0.25$2.00
250$0.63$5.00
500$1.00$8.00
750$1.38$11.00
1,000$1.75$14.00

Price per million tokens

Token typeGemini 3.1 Flash-LiteGemini 3.1 Pro Preview
Input$0.25$2
Cached input$0.025$0.20
Output$1.50$12
Batch input$0.125$1
Batch cached input$0.0125$0.20
Batch output$0.75$6

Gemini 3.1 Flash-Lite: Audio input costs more.

Gemini 3.1 Pro Preview: Prompts over 200K tokens are billed at a higher rate.

Standard rates in USD, before tax Gemini API pricing

Monthly cost for typical workloads

WorkloadGemini 3.1 Flash-LiteGemini 3.1 Pro Preview
Support chatbot
2,000 in / 300 out tokens, 1,000 requests a day, 50% cached
$21.75$174.00
Document summaries
10,000 in / 800 out tokens, 200 requests a day
$22.20$177.60
Tagging / classifying
400 in / 20 out tokens, 20,000 requests a day
$78.00$624.00
Standard rates in USD, before tax. A month is 30 days.

Or see Gemini 3.1 Flash-Lite pricing, Gemini 3.1 Pro Preview pricing, or compare any two models.

FAQ

Frequently asked questions

Is Gemini 3.1 Flash-Lite cheaper than Gemini 3.1 Pro Preview?

Gemini 3.1 Flash-Lite is cheaper than Gemini 3.1 Pro Preview at standard rates, with 8× cheaper input and 8× cheaper output. Based on standard API rates last checked on 30 Sept 2026.

How much do Gemini 3.1 Flash-Lite and Gemini 3.1 Pro Preview cost per million tokens?

Gemini 3.1 Flash-Lite: $0.25 per million input tokens and $1.50 per million output tokens. Gemini 3.1 Pro Preview: $2 input and $12 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 Flash-Lite’s batch rates are $0.125 input and $0.75 output per million tokens (50% off); Gemini 3.1 Pro Preview’s batch rates are $1 input and $6 output per million tokens (50% off).

Does prompt caching change the comparison?

Gemini 3.1 Flash-Lite charges $0.025 per million cached input tokens, against $0.25 for normal input; Gemini 3.1 Pro Preview charges $0.20 per million cached input tokens, against $2 for normal input. Cache write and storage charges are extra and aren’t included here.

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