Gemini 3.1 Pro vs Gemini 2.5 Flash-Lite

Detailed pricing comparison and cost analysis.

Updated April 2026

Cost Simulator

Gemini 3.1 Pro Cost
$4.40
Gemini 2.5 Flash-Lite Cost
$0.18
Gemini 2.5 Flash-Lite is 96% cheaper
FeatureGemini 3.1 ProGemini 2.5 Flash-Lite
ProviderGoogleGoogle
Input Price (1M)$2.00$0.10
Output Price (1M)$12.00$0.40
Context Window1,000,0001,000,000

Verdict

Gemini 3.1 Pro costs $2.00 per 1M input tokens and $12.00 per 1M output tokens. Gemini 2.5 Flash-Lite costs $0.10 per 1M input tokens and $0.40 per 1M output tokens. Gemini 2.5 Flash-Lite is 95% cheaper on input tokens than Gemini 3.1 Pro. For output tokens, Gemini 2.5 Flash-Lite is the more affordable option at $0.40/1M vs $12.00.

On context window, Gemini 3.1 Pro 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 Pro

  • ✓ You are already integrated with Google

When to choose Gemini 2.5 Flash-Lite

  • ✓ You need the lowest input token cost ($ 0.10/1M)
  • ✓ Your workload is output-heavy — Gemini 2.5 Flash-Lite generates text cheaper
  • ✓ 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 Pro cheaper than Gemini 2.5 Flash-Lite?

Gemini 2.5 Flash-Lite is cheaper on input tokens at $0.10/1M vs $2.00/1M for Gemini 3.1 Pro — a 95% saving.

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

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

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

The best choice depends on your use case. For cost efficiency on input tokens, Gemini 2.5 Flash-Lite is the cheaper option. For maximum context length, Gemini 3.1 Pro supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.