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o3-pro vs GPT-5.6 Terra

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

o3-pro Cost
$36.00
GPT-5.6 Terra Cost
$4.40
GPT-5.6 Terra is 88% cheaper
Featureo3-proGPT-5.6 Terra
ProviderOpenAIOpenAI
Input Price (1M)$20.00$2.00
Output Price (1M)$80.00$12.00
Context Window200,0001,000,000

Verdict

o3-pro costs $20.00 per 1M input tokens and $80.00 per 1M output tokens. GPT-5.6 Terra costs $2.00 per 1M input tokens and $12.00 per 1M output tokens. GPT-5.6 Terra is 90% cheaper on input tokens than o3-pro. For output tokens, GPT-5.6 Terra is the more affordable option at $12.00/1M vs $80.00.

On context window, GPT-5.6 Terra 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 o3-pro

  • ✓ You are already integrated with OpenAI

When to choose GPT-5.6 Terra

  • ✓ You need the lowest input token cost ($ 2.00/1M)
  • ✓ Your workload is output-heavy — GPT-5.6 Terra generates text cheaper
  • ✓ You need a larger context window (1,000,000 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 o3-pro cheaper than GPT-5.6 Terra?

GPT-5.6 Terra is cheaper on input tokens at $2.00/1M vs $20.00/1M for o3-pro — a 90% saving.

What is the context window of o3-pro vs GPT-5.6 Terra?

o3-pro has a 200,000-token context window. GPT-5.6 Terra has a 1,000,000-token context window. GPT-5.6 Terra supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: o3-pro or GPT-5.6 Terra?

The best choice depends on your use case. For cost efficiency on input tokens, GPT-5.6 Terra is the cheaper option. For maximum context length, GPT-5.6 Terra supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.