GPT-5 Nano

GPT-5 Nano is a tiny model in the GPT-5 lane for routing, extraction, classification, and bulk jobs. It is the first version of its line in the registry. It has a 400,000 token context window and a 128,000 token maximum output. It accepts image and text, returns text. It supports reasoning mode and tool calling. Weights are not open. Price starts at $0.04 per million input tokens and $0.32 per million output tokens. Cached input is $0.0045 per million tokens.

First version of its line in the registry.

Range across the hosts that serve it: up to $0.06 per 1M input tokens.

• ·400k token context window
• ·128k max output tokens
• ·Supports reasoning and tool calling
• ·Accepts image and text input
• ·Low price from $0.04 per million input tokens

• Reach for it for routing, extraction, classification, and bulk jobs
• Reach for it for handling large contexts up to 400k tokens
• Reach for it for tasks needing reasoning and tool calling
• Reach for it for image and text input processing

26 hosts serve this model at the price above · the maker's documentation

The registry keeps the six most recent versions of a line. Older ones stay in the file and can be surfaced without a rebuild.

What is the context window size?

The context window is 400,000 tokens.

Does it support image input?

Yes, it accepts image and text input, and returns text output.

Are the weights open?

No, the weights are not open.