Gemini 3.1 Pro vs Gemini 3 Flash

Gemini 3.1 Pro and Gemini 3 Flash are both current google production-tier models. Gemini 3 Flash is meaningfully cheaper at $0.50 / $3 per 1M. Gemini 3.1 Pro leads on coding, reasoning, general knowledge.

Specs side by side

Metric
Google
Gemini 3.1 Pro
Google
Gemini 3 Flash
Input price (per 1M)$2$0.5
Output price (per 1M)$12$3
Context window2M tokens1M tokens
Speed tierbalancedfast
Open weightsNoNo
EU regionYesYes
Free tierNoGoogle AI Studio
Prompt cachingYesYes
Vision inputYesYes
Extended thinkingYesYes

When to choose each

Google

Choose Gemini 3.1 Pro if…

  • You need 2M context (2× more than Gemini 3 Flash)
  • Coding is central to your workload
  • Reasoning is central to your workload
Google Free tier

Choose Gemini 3 Flash if…

  • Cost is a priority ($0.50 / $3 per 1M vs $2 / $12 per 1M)
  • You want a free tier for prototyping

Benchmark delta

Gemini 3.1 Pro leads on

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

Gemini 3 Flash leads on

Gemini 3 Flash has no meaningful benchmark lead in this pair.

FAQ — Gemini 3.1 Pro vs Gemini 3 Flash

Gemini 3.1 Pro vs Gemini 3 Flash — which is better?

Gemini 3.1 Pro and Gemini 3 Flash are both current google production-tier models. Gemini 3 Flash is meaningfully cheaper at $0.50 / $3 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 Pro pricing compare to Gemini 3 Flash?

Gemini 3.1 Pro costs $2 / $12 per 1M vs Gemini 3 Flash at $0.50 / $3 per 1M. Gemini 3 Flash is cheaper on output tokens by roughly 300%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.

Does Gemini 3.1 Pro or Gemini 3 Flash have the bigger context window?

Gemini 3.1 Pro has a 2M-token context window — 2× the 1M context of Gemini 3 Flash. Enough for entire codebases, books, or multi-document RAG.

Is there a free tier for Gemini 3.1 Pro or Gemini 3 Flash?

Gemini 3.1 Pro: no — Paid-only since 2026-04-01 (previously had free tier via AI Studio). Gemini 3 Flash: yes — Reduced daily quota; rate-limited for prototyping.

Which is better for coding — Gemini 3.1 Pro or Gemini 3 Flash?

Gemini 3.1 Pro leads on coding benchmarks (Gemini 3.1 Pro: 94/100, Gemini 3 Flash: 84/100). For production coding agents also weigh tool-use performance — Gemini 3.1 Pro scores 91, Gemini 3 Flash scores 85.