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o4-mini vs Gemini 3.1 Pro

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

o4-mini Cost
$1.98
Gemini 3.1 Pro Cost
$4.40
o4-mini is 55% cheaper
Featureo4-miniGemini 3.1 Pro
ProviderOpenAIGoogle
Input Price (1M)$1.10$2.00
Output Price (1M)$4.40$12.00
Context Window200,0001,000,000

Verdict

o4-mini costs $1.10 per 1M input tokens and $4.40 per 1M output tokens. Gemini 3.1 Pro costs $2.00 per 1M input tokens and $12.00 per 1M output tokens. o4-mini is 45% cheaper on input tokens than Gemini 3.1 Pro. For output tokens, o4-mini is the more affordable option at $4.40/1M vs $12.00.

On context window, Gemini 3.1 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 o4-mini

  • ✓ You need the lowest input token cost ($ 1.10/1M)
  • ✓ Your workload is output-heavy — o4-mini generates text cheaper
  • ✓ You are already integrated with OpenAI

When to choose Gemini 3.1 Pro

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

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 o4-mini cheaper than Gemini 3.1 Pro?

o4-mini is cheaper on input tokens at $1.10/1M vs $2.00/1M for Gemini 3.1 Pro — a 45% saving.

What is the context window of o4-mini vs Gemini 3.1 Pro?

o4-mini has a 200,000-token context window. Gemini 3.1 Pro has a 1,000,000-token context window. Gemini 3.1 Pro supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: o4-mini or Gemini 3.1 Pro?

The best choice depends on your use case. For cost efficiency on input tokens, o4-mini is the cheaper option. For maximum context length, Gemini 3.1 Pro supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.