# Limits

File length and size limits, concurrent separations, and how long results are kept.

## Lanes

Accounts with bought credits run on the paid lane. All other accounts run on the free lane.

|                     | Free lane  | Paid lane  |
| ------------------- | ---------- | ---------- |
| Longest file        | 10 minutes | 60 minutes |
| Largest file        | 95 MB      | 2 GB       |
| Separations at once | 1          | 3          |

Files over 95 MB require a [reserved upload](https://disband.io/docs/large-files), available on the paid lane only. `GET /usage` returns the limits that apply to the caller in `limits`.

## Running separations

A separation counts as running from its create or reservation until it is ready or fails. Another create returns `429` [`busy`](https://disband.io/docs/errors#busy) with `Retry-After`.

## Retention

Files are kept for one hour after a separation is ready or fails, then deleted with the separation. Download the stems within that hour.

## Keys

An account can have up to 20 API keys.