by OpenAI

GPT-6 Luna.

multimodal closed 1.1M ctx
Cheapest input
$0.1/M
on OpenRouter
Cheapest output
$0.5/M
on OpenRouter
Hosted equiv.
~$0.18/hr
@ 100 tok/s on OpenRouter
Description

About GPT-6 Luna.

GPT-6 Luna is the model OpenAI describes as its most efficient, intended for focused, high-volume tasks. It takes text and images and returns text, with no audio or video support. The context window is 1,050,000 tokens, output reaches 128,000 and knowledge stops at May 18, 2026. Reasoning effort runs from none to max, with medium as the default. In Chat Completions, function calling works only with reasoning set to none.

Context window

How much it can remember.

1.1M tokens ≈ 787,500 English words
4K 32K 128K 1M
Capabilities

What it can do.

· Vision input
· Audio input
· Video input
· Function calling
· Tool use
· JSON mode
✓ Streaming
· Fine-tuning