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GPT-5.5 Pro vs GPT-5 mini

Detailed pricing comparison and cost analysis.

Updated August 2026

Cost Simulator

GPT-5.5 Pro Cost
$66.00
GPT-5 mini Cost
$0.65
GPT-5 mini is 99% cheaper
FeatureGPT-5.5 ProGPT-5 mini
ProviderOpenAIOpenAI
Input Price (1M)$30.00$0.25
Output Price (1M)$180.00$2.00
Context Window1,000,000128,000

Verdict

GPT-5.5 Pro costs $30.00 per 1M input tokens and $180.00 per 1M output tokens. GPT-5 mini costs $0.25 per 1M input tokens and $2.00 per 1M output tokens. GPT-5 mini is 99% cheaper on input tokens than GPT-5.5 Pro. For output tokens, GPT-5 mini is the more affordable option at $2.00/1M vs $180.00.

On context window, GPT-5.5 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 GPT-5.5 Pro

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

When to choose GPT-5 mini

  • ✓ You need the lowest input token cost ($ 0.25/1M)
  • ✓ Your workload is output-heavy — GPT-5 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 GPT-5.5 Pro cheaper than GPT-5 mini?

GPT-5 mini is cheaper on input tokens at $0.25/1M vs $30.00/1M for GPT-5.5 Pro — a 99% saving.

What is the context window of GPT-5.5 Pro vs GPT-5 mini?

GPT-5.5 Pro has a 1,000,000-token context window. GPT-5 mini has a 128,000-token context window. GPT-5.5 Pro supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: GPT-5.5 Pro or GPT-5 mini?

The best choice depends on your use case. For cost efficiency on input tokens, GPT-5 mini is the cheaper option. For maximum context length, GPT-5.5 Pro supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.