# o1 pro

> A hundred and fifty dollars a million tokens in, six hundred out: the most expensive thing OpenAI has ever put behind an API, sold on the premise that some questions are worth more compute than others. It was o1 given longer to think. Nineteen months later it is switched off alongside the tier it defined.

2025-03-19 — still running · lived 1 year, 6 months · plot reserved

This URL is the guided walk — the 3D cemetery, standing at this grave. The written record is at [o1 pro's epitaph](https://models.rip/o1-pro/epitaph).

## Elsewhere

- [The whole cemetery](https://models.rip/)
- [The dataset](https://models.rip/graveyard.json)