GPT-5.6 Luna vs GPT-5.2

Detailed pricing comparison and cost analysis.

Updated July 2026

Cost Simulator

GPT-5.6 Luna Cost
$2.20
GPT-5.2 Cost
$4.55
GPT-5.6 Luna is 52% cheaper
FeatureGPT-5.6 LunaGPT-5.2
ProviderOpenAIOpenAI
Input Price (1M)$1.00$1.75
Output Price (1M)$6.00$14.00
Context Window1,000,000128,000

Verdict

GPT-5.6 Luna costs $1.00 per 1M input tokens and $6.00 per 1M output tokens. GPT-5.2 costs $1.75 per 1M input tokens and $14.00 per 1M output tokens. GPT-5.6 Luna is 43% cheaper on input tokens than GPT-5.2. For output tokens, GPT-5.6 Luna is the more affordable option at $6.00/1M vs $14.00.

On context window, GPT-5.6 Luna 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 Luna

  • ✓ You need the lowest input token cost ($ 1.00/1M)
  • ✓ Your workload is output-heavy — GPT-5.6 Luna generates text cheaper
  • ✓ You need a larger context window (1,000,000 tokens)
  • ✓ You are already integrated with OpenAI

When to choose GPT-5.2

  • ✓ 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 Luna cheaper than GPT-5.2?

GPT-5.6 Luna is cheaper on input tokens at $1.00/1M vs $1.75/1M for GPT-5.2 — a 43% saving.

What is the context window of GPT-5.6 Luna vs GPT-5.2?

GPT-5.6 Luna has a 1,000,000-token context window. GPT-5.2 has a 128,000-token context window. GPT-5.6 Luna supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: GPT-5.6 Luna or GPT-5.2?

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