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o3 vs Gemini 3 Flash

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

Quick Verdict

Gemini 3 Flash is cheaper than o3 at $0.50/1M/1M vs $2.00/1M/1M input tokens — a 4.0x cost difference. o3 scores higher on quality benchmarks (ELO 1395). Choose Gemini 3 Flash for cost-sensitive workloads; choose o3 for maximum quality.

Detailed Comparison

Metrico3Gemini 3 Flash
Input Price / 1M tokens$2.00/1M$0.50/1MCheaper
Output Price / 1M tokens$8.00/1M$3.00/1MCheaper
Context Window200K1MLarger
ELO Score (LMSYS)1395Smarter1370
Open Source
Free Tier
Release Date2025-042026-02

Which is cheaper: o3 or Gemini 3 Flash?

Gemini 3 Flash is the cheaper option at $0.50/1M per 1M input tokens, compared to $2.00/1M for o3. That is a 4.0x cost difference on input tokens. Output pricing follows a similar pattern: o3 charges $8.00/1M/1M vs $3.00/1M/1M for Gemini 3 Flash.

Which has better quality: o3 or Gemini 3 Flash?

Based on LMSYS Chatbot Arena rankings, o3 achieves a higher ELO score (1395 vs 1370), suggesting stronger performance on open-ended tasks. o3 excels at top-tier reasoning on math, science, and agentic tasks. Gemini 3 Flash is known for gemini 3-generation quality at flash pricing.

Which should you choose: o3 or Gemini 3 Flash?

Choose o3 if:
  • Top-tier reasoning on math, science, and agentic tasks
  • 87% cheaper than original o1 at the same capability tier
  • 200K context window
Choose Gemini 3 Flash if:
  • Gemini 3-generation quality at Flash pricing
  • 1M context window
  • Strong multimodal reasoning

Frequently Asked Questions

Which is cheaper: o3 or Gemini 3 Flash?

Gemini 3 Flash is cheaper at $0.50/1M per 1M input tokens, making it 4.0x more affordable.

Which has better quality: o3 or Gemini 3 Flash?

o3 scores higher on the LMSYS Chatbot Arena with an ELO of 1395, suggesting better overall quality for most tasks.

Which has a larger context window: o3 or Gemini 3 Flash?

Gemini 3 Flash has a larger context window at 1000K tokens.

Should I choose o3 or Gemini 3 Flash?

Choose Gemini 3 Flash if cost is the priority. Choose o3 if benchmark quality is most important. Consider your specific use case: o3 is best for reasoning and math, while Gemini 3 Flash excels at fast-response and function-calling.

Is o3 or Gemini 3 Flash open source?

o3 is proprietary. Gemini 3 Flash is proprietary.

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