Home › AI Models › Gemini 3.1 Pro vs Gemini 2.5 Flash

Gemini 3.1 Pro vs Gemini 2.5 Flash: price comparison

Real 2026 API prices side by side, with the total cost of a typical 10M-input / 3M-output monthly workload.

Price & cost at a glance

	Gemini 3.1 Pro	Gemini 2.5 Flash
Input / 1M tokens	$2	$0.3
Output / 1M tokens	$12	$2.5
Context window	2000K	1000K
Cost — 10M in + 3M out	$56	$10.5

Green = cheaper / larger. Prices per 1M tokens, USD. Snapshot 2026 — verify with the provider.

Which is cheaper?

Gemini 2.5 Flash is the cheaper option on a 10M-in / 3M-out workload — about $10.5/mo versus $56 for Gemini 3.1 Pro (~5.3× difference). Because output tokens are billed higher, the model with the lower output price usually wins as your responses get longer.

Run your own token mix in the cost calculator, or see each model in depth: Gemini 3.1 Pro · Gemini 2.5 Flash.

Frequently asked

Is Gemini 3.1 Pro or Gemini 2.5 Flash cheaper?

At a typical 10M input + 3M output tokens per month, Gemini 2.5 Flash costs about $10.5 versus $56 for Gemini 3.1 Pro — Gemini 2.5 Flash is roughly 5.3x cheaper on this workload. Your ratio of input to output tokens changes the gap.

What's the price difference between Gemini 3.1 Pro and Gemini 2.5 Flash?

Gemini 3.1 Pro is $2/$12 per 1M input/output tokens; Gemini 2.5 Flash is $0.3/$2.5. Output tokens usually dominate a bill, so compare the output price first.

Which has the bigger context window, Gemini 3.1 Pro or Gemini 2.5 Flash?

Gemini 3.1 Pro supports about 2000K tokens and Gemini 2.5 Flash about 1000K. A bigger window costs more per call because every token in context is billed.

Related comparisons

GPT-5 vs Gemini 3.1 Pro Claude Opus 4.8 vs Gemini 3.1 Pro GPT-4o mini vs Gemini 2.5 Flash All 387 models →

Educational estimates — not affiliated with any provider.