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o1 vs GPT-5 Pro

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

o1 Cost
$27.00
GPT-5 Pro Cost
$39.00
o1 is 31% cheaper
Featureo1GPT-5 Pro
ProviderOpenAIOpenAI
Input Price (1M)$15.00$15.00
Output Price (1M)$60.00$120.00
Context Window200,000400,000

Verdict

o1 costs $15.00 per 1M input tokens and $60.00 per 1M output tokens. GPT-5 Pro costs $15.00 per 1M input tokens and $120.00 per 1M output tokens. o1 and GPT-5 Pro have identical input token pricing. For output tokens, o1 is the more affordable option at $60.00/1M vs $120.00.

On context window, GPT-5 Pro supports 400,000 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 o1

  • ✓ Your workload is output-heavy — o1 generates text cheaper
  • ✓ You are already integrated with OpenAI

When to choose GPT-5 Pro

  • ✓ You need a larger context window (400,000 tokens)
  • ✓ 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 o1 cheaper than GPT-5 Pro?

o1 and GPT-5 Pro have identical input token pricing at $15.00/1M tokens.

What is the context window of o1 vs GPT-5 Pro?

o1 has a 200,000-token context window. GPT-5 Pro has a 400,000-token context window. GPT-5 Pro supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: o1 or GPT-5 Pro?

The best choice depends on your use case. For cost efficiency on input tokens, o1 is the cheaper option. For maximum context length, GPT-5 Pro supports 400,000 tokens. Use the comparison table above to find the right fit for your workload.