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PricesCompare → Gemini 3.7 Flash vs Gemini 3.1 Pro

Gemini 3.7 Flash vs Gemini 3.1 Pro: API cost compared

Gemini 3.7 Flash lists at $0.750 in / $3.750 out per 1M tokens. Gemini 3.1 Pro lists at $2.000 in / $12.00. Sticker price only tells you so much — below is what each actually costs across eight production workloads.

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Cheaper on more workloads
Gemini 3.7 Flash
wins 8 of 8
Blended rate gap
3.0x
at 3:1 in:out

Side by side

Gemini 3.7 FlashGemini 3.1 Pro
ProviderGoogleGoogle
Input per 1M$0.750$2.000
Output per 1M$3.750$12.00
Cached input per 1Mnot publishednot published
Context window1M1M
Blended per 1M (3:1)$1.500$4.500

Monthly cost by workload

Caching applied at each workload's typical hit rate. This is where the two models actually separate.

WorkloadGemini 3.7 FlashGemini 3.1 ProCheaperDifference
Customer support chatbot$133.12$390.00Gemini 3.7 Flash$256.88 (66%)
RAG document Q&A$165.00$464.00Gemini 3.7 Flash$299.00 (64%)
Coding agent$120.00$344.00Gemini 3.7 Flash$224.00 (65%)
Bulk summarization$1,050$2,880Gemini 3.7 Flash$1,830 (64%)
Structured data extraction$1,781$5,000Gemini 3.7 Flash$3,219 (64%)
Long-form content generation$165.00$520.00Gemini 3.7 Flash$355.00 (68%)
Email triage agent$487.50$1,360Gemini 3.7 Flash$872.50 (64%)
Translation pipeline$1,069$3,330Gemini 3.7 Flash$2,261 (68%)
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How to read this

Gemini 3.7 Flash is cheaper on the majority of these workloads, but "majority" is not the decision. The output:input price ratio is 5.0 for Gemini 3.7 Flash and 6.0 for Gemini 3.1 Pro. If your traffic is output-heavy — long-form drafting, translation — the model with the lower output price wins regardless of what the input price suggests. If you are input-heavy — RAG, bulk summarization, agents re-reading a codebase — the cached input rate matters more than either headline number.

Cost is also not the only axis. This site does not benchmark quality, latency, or rate limits, and a model that is 3x cheaper but needs two attempts per task is not cheaper. Use these numbers to size a bill, then validate on your own evals.

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Cost calculator

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Cheapest model
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ModelIn /1MOut /1MMonthlyvs best