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o3-mini vs Gemini 2.5 Flash

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

Quick Verdict

Gemini 2.5 Flash is cheaper than o3-mini at $0.30/1M vs $1.10/1M input tokens — a 3.7x cost difference. Both models have comparable benchmark scores. Choose Gemini 2.5 Flash for cost-sensitive workloads; both are strong choices depending on your budget.

Detailed Comparison

Metrico3-miniGemini 2.5 Flash
Input Price / 1M tokens$1.10/1M$0.30/1MCheaper
Output Price / 1M tokens$4.40/1M$2.50/1MCheaper
Context Window200K1MLarger
ELO Score (LMSYS)13401340
Open Source
Free Tier
Release Date2025-012025-06

Which is cheaper: o3-mini or Gemini 2.5 Flash?

Gemini 2.5 Flash is the cheaper option at $0.30/1M per 1M input tokens, compared to $1.10/1M for o3-mini. That is a 3.7x cost difference on input tokens. Output pricing follows a similar pattern: o3-mini charges $4.40/1M vs $2.50/1M for Gemini 2.5 Flash.

Which has better quality: o3-mini or Gemini 2.5 Flash?

Based on LMSYS Chatbot Arena rankings, o3-mini achieves a higher ELO score (1340 vs 1340), suggesting stronger performance on open-ended tasks. o3-mini excels at strong reasoning at a low price point. Gemini 2.5 Flash is known for excellent price-performance at flash tier.

Which should you choose: o3-mini or Gemini 2.5 Flash?

Choose o3-mini if:
  • Strong reasoning at a low price point
  • 200K context window
  • Three effort levels (low/medium/high) for cost control
Choose Gemini 2.5 Flash if:
  • Excellent price-performance at Flash tier
  • 1M token context window
  • Native multimodal

Frequently Asked Questions

Which is cheaper: o3-mini or Gemini 2.5 Flash?

Gemini 2.5 Flash is cheaper at $0.30/1M per 1M input tokens, making it 3.7x more affordable.

Which has better quality: o3-mini or Gemini 2.5 Flash?

Both models have similar quality rankings on available benchmarks.

Which has a larger context window: o3-mini or Gemini 2.5 Flash?

Gemini 2.5 Flash has a larger context window at 1000K tokens.

Should I choose o3-mini or Gemini 2.5 Flash?

Choose Gemini 2.5 Flash if cost is the priority. Consider your specific use case: o3-mini is best for reasoning and math, while Gemini 2.5 Flash excels at fast-response and low-cost.

Is o3-mini or Gemini 2.5 Flash open source?

o3-mini is proprietary. Gemini 2.5 Flash is proprietary.

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