GPT-5.6 Luna

OpenAI · GPT-5.6 · budget · released Jul 9, 2026 · gpt-5.6-luna

GPT-5.6 family:GPT-5.6 Sol·GPT-5.6 Terra·GPT-5.6 Luna

Fast, cost-efficient tier of the GPT-5.6 series for high-volume, latency-sensitive work such as chat, classification, and lightweight agents.

Pricing

Input$1 / 1M checked Jul 19, 2026
Output$6 / 1M checked Jul 19, 2026

A Pro serving mode (reasoning.mode=pro) is available at the same list price.

Cost bandBudget
Free tierNo free API tier.

Limits

Context window1M checked Jul 19, 2026
DeploymentOpenAI API
OpenAI-compatible APIYes
ModalitiesText, Image input, PDF input

Where it fits

Best forHigh-volume chat, classification, extraction, and light agent steps.
Business fitHigh-volume option with capable reasoning at a fraction of flagship cost.

Capabilities

Reasoning modesFunction callingStructured outputsWeb searchMCP

Change history

Data

Last checkedJul 19, 2026
Cross-checked againstopenrouter.ai/openai/gpt-5.6-luna

Verify with provider documentation before committing spend. Report an error and it gets fixed with a logged correction.

Open in the comparison table JSON API