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Gemini 1.5 Flash vs Gemini 1.5 Pro

Pricing, context window, and benchmark comparison · Last updated April 2026

Quick Verdict

Gemini 1.5 Flash is cheaper than Gemini 1.5 Pro at $0.07/1M/1M vs $1.25/1M/1M input tokens — a 16.7x cost difference. Gemini 1.5 Pro scores higher on quality benchmarks (ELO 1266). Choose Gemini 1.5 Flash for cost-sensitive workloads; choose Gemini 1.5 Pro for maximum quality.

Detailed Comparison

MetricGemini 1.5 FlashGemini 1.5 Pro
Input Price / 1M tokens$0.07/1MCheaper$1.25/1M
Output Price / 1M tokens$0.30/1MCheaper$5.00/1M
Context Window1M2MLarger
ELO Score (LMSYS)12111266Smarter
Open Source
Free Tier
Release Date2024-052024-02

Which is cheaper: Gemini 1.5 Flash or Gemini 1.5 Pro?

Gemini 1.5 Flash is the cheaper option at $0.07/1M per 1M input tokens, compared to $1.25/1M for Gemini 1.5 Pro. That is a 16.7x cost difference on input tokens. Output pricing follows a similar pattern: Gemini 1.5 Flash charges $0.30/1M/1M vs $5.00/1M/1M for Gemini 1.5 Pro.

Which has better quality: Gemini 1.5 Flash or Gemini 1.5 Pro?

Based on LMSYS Chatbot Arena rankings, Gemini 1.5 Pro achieves a higher ELO score (1266 vs 1211), suggesting stronger performance on open-ended tasks. Gemini 1.5 Flash excels at one of the cheapest high-quality models available. Gemini 1.5 Pro is known for 2m token context window — largest available commercially.

Which should you choose: Gemini 1.5 Flash or Gemini 1.5 Pro?

Choose Gemini 1.5 Flash if:
  • One of the cheapest high-quality models available
  • 1M token context window
  • Very fast inference
Choose Gemini 1.5 Pro if:
  • 2M token context window — largest available commercially
  • Strong multimodal capabilities (text, images, video, audio)
  • Excellent price-to-quality ratio

Frequently Asked Questions

Which is cheaper: Gemini 1.5 Flash or Gemini 1.5 Pro?

Gemini 1.5 Flash is cheaper at $0.07/1M per 1M input tokens, making it 16.7x more affordable.

Which has better quality: Gemini 1.5 Flash or Gemini 1.5 Pro?

Gemini 1.5 Pro scores higher on the LMSYS Chatbot Arena with an ELO of 1266, suggesting better overall quality for most tasks.

Which has a larger context window: Gemini 1.5 Flash or Gemini 1.5 Pro?

Gemini 1.5 Pro has a larger context window at 2000K tokens.

Should I choose Gemini 1.5 Flash or Gemini 1.5 Pro?

Choose Gemini 1.5 Flash if cost is the priority. Choose Gemini 1.5 Pro if benchmark quality is most important. Consider your specific use case: Gemini 1.5 Flash is best for low-cost and fast-response, while Gemini 1.5 Pro excels at long-context and document-analysis.

Is Gemini 1.5 Flash or Gemini 1.5 Pro open source?

Gemini 1.5 Flash is proprietary. Gemini 1.5 Pro is proprietary.

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