Gemini 3.1 Flash-Lite vs Gemini 2.5 Pro

Detailed pricing comparison and cost analysis.

Updated April 2026

Cost Simulator

Gemini 3.1 Flash-Lite Cost
$0.55
Gemini 2.5 Pro Cost
$3.25
Gemini 3.1 Flash-Lite is 83% cheaper
FeatureGemini 3.1 Flash-LiteGemini 2.5 Pro
ProviderGoogleGoogle
Input Price (1M)$0.25$1.25
Output Price (1M)$1.50$10.00
Context Window1,000,0001,000,000

Verdict

Gemini 3.1 Flash-Lite costs $0.25 per 1M input tokens and $1.50 per 1M output tokens. Gemini 2.5 Pro costs $1.25 per 1M input tokens and $10.00 per 1M output tokens. Gemini 3.1 Flash-Lite is 80% cheaper on input tokens than Gemini 2.5 Pro. For output tokens, Gemini 3.1 Flash-Lite is the more affordable option at $1.50/1M vs $10.00.

On context window, Gemini 3.1 Flash-Lite supports 1,000,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.

When to choose Gemini 3.1 Flash-Lite

  • ✓ You need the lowest input token cost ($ 0.25/1M)
  • ✓ Your workload is output-heavy — Gemini 3.1 Flash-Lite generates text cheaper
  • ✓ You are already integrated with Google

When to choose Gemini 2.5 Pro

  • ✓ You are already integrated with Google

Use the calculator above to simulate your specific workload and find the exact break-even point. For most applications, the cheapest model is the one that minimises your total monthly bill given your input-to-output token ratio.

Frequently Asked Questions

Is Gemini 3.1 Flash-Lite cheaper than Gemini 2.5 Pro?

Gemini 3.1 Flash-Lite is cheaper on input tokens at $0.25/1M vs $1.25/1M for Gemini 2.5 Pro — a 80% saving.

What is the context window of Gemini 3.1 Flash-Lite vs Gemini 2.5 Pro?

Gemini 3.1 Flash-Lite has a 1,000,000-token context window. Gemini 2.5 Pro has a 1,000,000-token context window. Gemini 3.1 Flash-Lite supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: Gemini 3.1 Flash-Lite or Gemini 2.5 Pro?

The best choice depends on your use case. For cost efficiency on input tokens, Gemini 3.1 Flash-Lite is the cheaper option. For maximum context length, Gemini 3.1 Flash-Lite supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.