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GPT-5 vs GPT-5.1

Detailed pricing comparison and cost analysis.

Updated August 2026

Cost Simulator

GPT-5 Cost
$3.25
GPT-5.1 Cost
$3.25
GPT-5.1 is 0% cheaper
FeatureGPT-5GPT-5.1
ProviderOpenAIOpenAI
Input Price (1M)$1.25$1.25
Output Price (1M)$10.00$10.00
Context Window400,000400,000

Verdict

GPT-5 costs $1.25 per 1M input tokens and $10.00 per 1M output tokens. GPT-5.1 costs $1.25 per 1M input tokens and $10.00 per 1M output tokens. GPT-5 and GPT-5.1 have identical input token pricing. For output tokens, GPT-5 is the more affordable option at $10.00/1M vs $10.00.

On context window, GPT-5 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 GPT-5

  • ✓ You are already integrated with OpenAI

When to choose GPT-5.1

  • ✓ 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 cheaper than GPT-5.1?

GPT-5 and GPT-5.1 have identical input token pricing at $1.25/1M tokens.

What is the context window of GPT-5 vs GPT-5.1?

GPT-5 has a 400,000-token context window. GPT-5.1 has a 400,000-token context window. GPT-5 supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: GPT-5 or GPT-5.1?

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