GPT-5.6 Luna API Cost Calculator

OpenAI's GPT-5.6 Luna: $0.2/M input · $1.2/M output · $0.02/M cached input. Price your own workload below.

Presets:

What GPT-5.6 Luna costs in practice

WorkloadInputOutputCost
Short chat message500250$0.0004
10-page document + summary7,000500$0.0020
Agent / coding session50,00010,000$0.022
1M tokens in + 1M out1,000,0001,000,000$1.40

GPT-5.6 Luna vs nearest rivals

Closest-priced alternatives on a mixed 10K-input / 2K-output request:

ModelInput $/MTokOutput $/MTokMixed request
GPT-5.6 Luna$0.2$1.2$0.0044
DeepSeek V4 Flash$0.14$0.28$0.0020
Mistral Small 4$0.15$0.6$0.0027
DeepSeek V4 Pro$0.435$0.87$0.0061

Frequently asked questions

How much does the GPT-5.6 Luna API cost?

GPT-5.6 Luna costs $0.2 per million input tokens and $1.2 per million output tokens, with cached input at $0.02 per million (90% off).

How much does a typical chat message cost with GPT-5.6 Luna?

A short chat message (about 500 input and 250 output tokens) costs roughly $0.0004 with GPT-5.6 Luna. At 1,000 such requests a day, that is about $12.00 per month.

Is GPT-5.6 Luna cheap compared to similar models?

GPT-5.6 Luna has the #6 cheapest input rate of the 26 models we track. On a mixed workload (10K input / 2K output), it costs $0.0044 per request, versus $0.0020 for DeepSeek V4 Flash and $0.0061 for DeepSeek V4 Pro.

Related

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Last updated 2026-08-03. Prices verified againstOpenAI's official pricing page; see themethodology.