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Gemini 2.5 Pro vs o3-mini

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

Gemini 2.5 Pro Cost
$3.25
o3-mini Cost
$1.98
o3-mini is 39% cheaper
FeatureGemini 2.5 Proo3-mini
ProviderGoogleOpenAI
Input Price (1M)$1.25$1.10
Output Price (1M)$10.00$4.40
Context Window1,000,000200,000

Verdict

Gemini 2.5 Pro costs $1.25 per 1M input tokens and $10.00 per 1M output tokens. o3-mini costs $1.10 per 1M input tokens and $4.40 per 1M output tokens. o3-mini is 12% cheaper on input tokens than Gemini 2.5 Pro. For output tokens, o3-mini is the more affordable option at $4.40/1M vs $10.00.

On context window, Gemini 2.5 Pro supports 1,000,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.

When to choose Gemini 2.5 Pro

  • ✓ You need a larger context window (1,000,000 tokens)
  • ✓ You are already integrated with Google

When to choose o3-mini

  • ✓ You need the lowest input token cost ($ 1.10/1M)
  • ✓ Your workload is output-heavy — o3-mini generates text cheaper
  • ✓ You are already integrated with OpenAI

Use the calculator above to simulate your specific workload and find the exact break-even point. For most applications, the cheapest model is the one that minimises your total monthly bill given your input-to-output token ratio.

Frequently Asked Questions

Is Gemini 2.5 Pro cheaper than o3-mini?

o3-mini is cheaper on input tokens at $1.10/1M vs $1.25/1M for Gemini 2.5 Pro — a 12% saving.

What is the context window of Gemini 2.5 Pro vs o3-mini?

Gemini 2.5 Pro has a 1,000,000-token context window. o3-mini has a 200,000-token context window. Gemini 2.5 Pro supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: Gemini 2.5 Pro or o3-mini?

The best choice depends on your use case. For cost efficiency on input tokens, o3-mini is the cheaper option. For maximum context length, Gemini 2.5 Pro supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.