Comparison

Gemini 3.1 Pro Preview vs Gemini 3.5 Flash

Per input token, Gemini 3.5 Flash runs 25% cheaper than Gemini 3.1 Pro Preview. On generated (output) tokens, Gemini 3.1 Pro Preview costs 25% more than Gemini 3.5 Flash.

FieldGemini 3.1 Pro Preview
Gemini 3.5 Flash
ProviderGoogleGoogle
Context window1M
Max output65.5K
Input / 1M$2.00$1.5025% cheaper
Output / 1M$12.00$9.0025% cheaper
Cached input / 1M$0.20$0.1525% cheaper
Batch discount50%50%
Release date

Worked cost examples

Estimated monthly cost on three common usage shapes

WorkloadGemini 3.1 Pro PreviewGemini 3.5 Flash

Chatbot

800 input / 200 output tokens per request, 100,000 requests/month

$400.00$300.00cheaper

RAG pipeline

6,000 input / 700 output tokens per request, 30,000 requests/month

$612.00$459.00cheaper

Batch summarization

20,000 input / 1,500 output tokens per request, 5,000 requests/month

$290.00$217.50cheaper

Gemini 3.1 Pro Preview vs Gemini 3.5 Flash FAQ

Is Gemini 3.1 Pro Preview cheaper than Gemini 3.5 Flash?
Gemini 3.1 Pro Preview costs $2.00 per 1M input tokens versus $1.50 for Gemini 3.5 Flash — Gemini 3.5 Flash is 33% cheaper per input token.
Which is cheaper for output tokens, Gemini 3.1 Pro Preview or Gemini 3.5 Flash?
Gemini 3.1 Pro Preview charges $12.00 per 1M output tokens; Gemini 3.5 Flash charges $9.00 per 1M output tokens.
Do Gemini 3.1 Pro Preview and Gemini 3.5 Flash offer cache pricing?
Gemini 3.1 Pro Preview discounts cached input to $0.20 per 1M tokens. Gemini 3.5 Flash discounts cached input to $0.15 per 1M tokens.

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