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o3 vs Gemini 1.5 Pro

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

Quick Verdict

Gemini 1.5 Pro is cheaper than o3 at $1.25/1M/1M vs $10.00/1M/1M input tokens — a 8.0x cost difference. o3 scores higher on quality benchmarks (ELO 1380). Choose Gemini 1.5 Pro for cost-sensitive workloads; choose o3 for maximum quality.

Detailed Comparison

Metrico3Gemini 1.5 Pro
Input Price / 1M tokens$10.00/1M$1.25/1MCheaper
Output Price / 1M tokens$40.00/1M$5.00/1MCheaper
Context Window200K2MLarger
ELO Score (LMSYS)1380Smarter1266
Open Source
Free Tier
Release Date2025-042024-02

Which is cheaper: o3 or Gemini 1.5 Pro?

Gemini 1.5 Pro is the cheaper option at $1.25/1M per 1M input tokens, compared to $10.00/1M for o3. That is a 8.0x cost difference on input tokens. Output pricing follows a similar pattern: o3 charges $40.00/1M/1M vs $5.00/1M/1M for Gemini 1.5 Pro.

Which has better quality: o3 or Gemini 1.5 Pro?

Based on LMSYS Chatbot Arena rankings, o3 achieves a higher ELO score (1380 vs 1266), suggesting stronger performance on open-ended tasks. o3 excels at highest reasoning benchmark scores of any model. Gemini 1.5 Pro is known for 2m token context window — largest available commercially.

Which should you choose: o3 or Gemini 1.5 Pro?

Choose o3 if:
  • Highest reasoning benchmark scores of any model
  • Better cost-efficiency than o1 at similar quality
  • Superior at agentic and multi-step tasks
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: o3 or Gemini 1.5 Pro?

Gemini 1.5 Pro is cheaper at $1.25/1M per 1M input tokens, making it 8.0x more affordable.

Which has better quality: o3 or Gemini 1.5 Pro?

o3 scores higher on the LMSYS Chatbot Arena with an ELO of 1380, suggesting better overall quality for most tasks.

Which has a larger context window: o3 or Gemini 1.5 Pro?

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

Should I choose o3 or Gemini 1.5 Pro?

Choose Gemini 1.5 Pro 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 1.5 Pro excels at long-context and document-analysis.

Is o3 or Gemini 1.5 Pro open source?

o3 is proprietary. Gemini 1.5 Pro is proprietary.

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