o3 vs Gemini 2.5 Pro
Pricing, context window, and benchmark comparison · Last updated April 2026
Gemini 2.5 Pro is cheaper than o3 at $1.25/1M/1M vs $2.00/1M/1M input tokens — a 1.6x cost difference. o3 scores higher on quality benchmarks (ELO 1395). Choose Gemini 2.5 Pro for cost-sensitive workloads; choose o3 for maximum quality.
Which is cheaper: o3 or Gemini 2.5 Pro?
Gemini 2.5 Pro is the cheaper option at $1.25/1M per 1M input tokens, compared to $2.00/1M for o3. That is a 1.6x cost difference on input tokens. Output pricing follows a similar pattern: o3 charges $8.00/1M/1M vs $10.00/1M/1M for Gemini 2.5 Pro.
Which has better quality: o3 or Gemini 2.5 Pro?
Based on LMSYS Chatbot Arena rankings, o3 achieves a higher ELO score (1395 vs 1385), suggesting stronger performance on open-ended tasks. o3 excels at top-tier reasoning on math, science, and agentic tasks. Gemini 2.5 Pro is known for 2m token context window — among the largest available.
Which should you choose: o3 or Gemini 2.5 Pro?
- → Top-tier reasoning on math, science, and agentic tasks
- → 87% cheaper than original o1 at the same capability tier
- → 200K context window
- → 2M token context window — among the largest available
- → Strong multimodal reasoning across text, video, and audio
- → Excellent price-to-quality ratio vs. flagships
Frequently Asked Questions
Which is cheaper: o3 or Gemini 2.5 Pro?
Gemini 2.5 Pro is cheaper at $1.25/1M per 1M input tokens, making it 1.6x more affordable.
Which has better quality: o3 or Gemini 2.5 Pro?
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 2.5 Pro?
Gemini 2.5 Pro has a larger context window at 2000K tokens.
Should I choose o3 or Gemini 2.5 Pro?
Choose Gemini 2.5 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 2.5 Pro excels at long-context and document-analysis.
Is o3 or Gemini 2.5 Pro open source?
o3 is proprietary. Gemini 2.5 Pro is proprietary.