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GPT-5.6 Terra vs o4-mini

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

GPT-5.6 Terra Cost
$4.40
o4-mini Cost
$1.98
o4-mini is 55% cheaper
FeatureGPT-5.6 Terrao4-mini
ProviderOpenAIOpenAI
Input Price (1M)$2.00$1.10
Output Price (1M)$12.00$4.40
Context Window1,000,000200,000

Verdict

GPT-5.6 Terra costs $2.00 per 1M input tokens and $12.00 per 1M output tokens. o4-mini costs $1.10 per 1M input tokens and $4.40 per 1M output tokens. o4-mini is 45% cheaper on input tokens than GPT-5.6 Terra. For output tokens, o4-mini is the more affordable option at $4.40/1M vs $12.00.

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 GPT-5.6 Terra

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

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

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-5.6 Terra cheaper than o4-mini?

o4-mini is cheaper on input tokens at $1.10/1M vs $2.00/1M for GPT-5.6 Terra — a 45% saving.

What is the context window of GPT-5.6 Terra vs o4-mini?

GPT-5.6 Terra has a 1,000,000-token context window. o4-mini has a 200,000-token context window. GPT-5.6 Terra supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: GPT-5.6 Terra or o4-mini?

The best choice depends on your use case. For cost efficiency on input tokens, o4-mini 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.