Gemini 2.5 Flash vs Gemini 3.1 Pro

Compare Google and Google AI models

Google

Gemini 2.5 Flash

Google

Gemini 3.1 Pro

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Cost Comparison (1000 input + 500 output tokens, 100 requests/day)

Gemini 2.5 Flash

Per Request:$0.001550

Daily:$0.155

Monthly:$4.65

Yearly:$56.575

Gemini 3.1 Pro

Per Request:$0.008000

Daily:$0.80

Monthly:$24.00

Yearly:$292.00

Cost Differences

+$0.006450

Per Request

+$0.645

Daily

+$19.35

Monthly

+$235.425

Yearly

Gemini 3.1 Pro costs more than Gemini 2.5 Flash

Feature Comparison

Feature	Gemini 2.5 Flash	Gemini 3.1 Pro
Provider	Google	Google
Input Price	$0.30/1M tokens	$2.00/1M tokens
Output Price	$2.50/1M tokens	$12.00/1M tokens
Context Window	1,000,000 tokens	1,000,000 tokens
Max Output	32,768 tokens	65,536 tokens
Category	efficient	flagship
Capabilities	textvisionaudiocode	textvisionaudiovideocodereasoning
Release Date	5/20/2025	2/19/2026

Gemini 2.5 Flash vs Gemini 3.1 Pro: Which Should You Choose?

Choosing between Gemini 2.5 Flash and Gemini 3.1 Pro depends on your priorities: cost efficiency, context length, or raw capability. Gemini 2.5 Flash is the more affordable option at $0.30/1M input tokens — 85% cheaper than Gemini 3.1 Pro.

These models target different tiers: Gemini 2.5 Flash is a efficient model while Gemini 3.1 Pro is flagship. This means they're optimized for different workloads. Gemini 3.1 Pro targets more demanding workloads, while Gemini 2.5 Flash provides a cost-effective option for everyday tasks.

Output costs matter too. Gemini 2.5 Flash charges $2.50/1M output tokens vs $12.00 for Gemini 3.1 Pro. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Gemini 2.5 Flash has the edge here at $2.50/1M output tokens.

Multimodal capabilities: Both models support vision (image understanding), so you can send images alongside text prompts with either option.

Best Use Cases

Choose Gemini 2.5 Flash when:

• Budget is a primary concern
• You're already using Google's API ecosystem
• You're running high-volume, latency-sensitive workloads

Choose Gemini 3.1 Pro when:

• You need more capabilities (video, reasoning)
• You need longer outputs (up to 65,536 tokens)
• You're already using Google's API ecosystem

Try Different Scenarios

Use the calculator below to see how costs change with different usage patterns

Gemini 2.5 Flash (Google)

Cost Calculator

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Gemini 3.1 Pro (Google)

Cost Calculator

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Model

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Frequently Asked Questions

Which is cheaper, Gemini 2.5 Flash or Gemini 3.1 Pro?▼

Gemini 2.5 Flash is cheaper for input tokens at $0.30 per million tokens vs $2.00 for Gemini 3.1 Pro — that's 85% savings on input costs.

What is the context window difference between Gemini 2.5 Flash and Gemini 3.1 Pro?▼

Gemini 2.5 Flash supports 1,000,000 tokens while Gemini 3.1 Pro supports 1,000,000 tokens — a difference of 0 tokens in favor of Gemini 2.5 Flash.

Which model is better for AI Chatbot?▼

Both models support text. For ai chatbot, Gemini 2.5 Flash is the lower-cost option, while Gemini 2.5 Flash offers a larger context window (1,000,000 vs 1,000,000 tokens). Choose Gemini 2.5 Flash for budget sensitivity or Gemini 2.5 Flash for longer context tasks.

Which model has better overall pricing for heavy usage?▼

At 100 requests/day with 1,000 input and 500 output tokens each, Gemini 2.5 Flash costs about $4.65/month and Gemini 3.1 Pro costs about $24.00/month. Overall, Gemini 2.5 Flash has lower combined input + output rates ($0.30 in, $2.50 out) vs Gemini 3.1 Pro.