Simon Willison’s Weblog

GPT-4o Long Output (via) "OpenAI is offering an experimental version of GPT-4o with a maximum of 64K output tokens per request."

It's a new model (for alpha testers only) called gpt-4o-64k-output-alpha that costs $6/million input tokens and $18/million output tokens.

That's a little bit more than GPT-4o ($5/$15) and a LOT more than GPT-4o mini ($0.15/$0.60).

Long output is primarily useful for data transformation use-cases - things like translating documents from one language into another, or extracting structured data from documents where almost every input token is needed in the output JSON.

Prior to this the longest output model I knew of was GPT-4o mini, at 16,000 tokens. Most of OpenAI's competitors still cap out at around 4,000 or 8,000.