Gemini 3.1 Flash-Lite vs Gemini 3.1 Pro

Gemini 3.1 Flash-Lite and Gemini 3.1 Pro are both current google production-tier models. Gemini 3.1 Flash-Lite is meaningfully cheaper at $0.25 / $1.5 per 1M. Gemini 3.1 Pro leads on coding, reasoning, general knowledge.

Specs side by side

Metric
Google
Gemini 3.1 Flash-Lite
Google
Gemini 3.1 Pro
Input price (per 1M)$0.25$2
Output price (per 1M)$1.5$12
Context window1M tokens2M tokens
Speed tierultrabalanced
Open weightsNoNo
EU regionYesYes
Free tierGoogle AI StudioNo
Prompt cachingNoYes
Vision inputYesYes
Extended thinkingNoYes

When to choose each

Google Free tier

Choose Gemini 3.1 Flash-Lite if…

  • Cost is a priority ($0.25 / $1.5 per 1M vs $2 / $12 per 1M)
  • Low latency matters (ultra vs balanced)
  • You want a free tier for prototyping
Google

Choose Gemini 3.1 Pro if…

  • You need 2M context (2× more than Gemini 3.1 Flash-Lite)
  • HIPAA eligibility is required
  • Coding is central to your workload
  • Reasoning is central to your workload

Benchmark delta

Gemini 3.1 Flash-Lite leads on

Gemini 3.1 Flash-Lite has no meaningful benchmark lead in this pair.

Gemini 3.1 Pro leads on

  • Coding
  • Reasoning
  • General knowledge
  • Long-context retrieval
  • Instruction following
  • Multilingual
  • Vision
  • Tool use

FAQ — Gemini 3.1 Flash-Lite vs Gemini 3.1 Pro

Gemini 3.1 Flash-Lite vs Gemini 3.1 Pro — which is better?

Gemini 3.1 Flash-Lite and Gemini 3.1 Pro are both current google production-tier models. Gemini 3.1 Flash-Lite is meaningfully cheaper at $0.25 / $1.5 per 1M. Gemini 3.1 Pro leads on coding, reasoning, general knowledge. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.

How does Gemini 3.1 Flash-Lite pricing compare to Gemini 3.1 Pro?

Gemini 3.1 Flash-Lite costs $0.25 / $1.5 per 1M vs Gemini 3.1 Pro at $2 / $12 per 1M. Gemini 3.1 Flash-Lite is cheaper on output tokens by roughly 700%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.

Does Gemini 3.1 Flash-Lite or Gemini 3.1 Pro have the bigger context window?

Gemini 3.1 Pro has a 2M-token context window — 2× the 1M context of Gemini 3.1 Flash-Lite. Enough for entire codebases, books, or multi-document RAG.

Is there a free tier for Gemini 3.1 Flash-Lite or Gemini 3.1 Pro?

Gemini 3.1 Flash-Lite: yes — Reduced daily quota; most generous free tier of any frontier lab. Gemini 3.1 Pro: no — Paid-only since 2026-04-01 (previously had free tier via AI Studio).

Which is better for coding — Gemini 3.1 Flash-Lite or Gemini 3.1 Pro?

Gemini 3.1 Pro leads on coding benchmarks (Gemini 3.1 Flash-Lite: 72/100, Gemini 3.1 Pro: 94/100). For production coding agents also weigh tool-use performance — Gemini 3.1 Flash-Lite scores 76, Gemini 3.1 Pro scores 91.