# Limits (/tools/s3-gateway/limits)

| Limit                            | Value                                         | Amazon S3   | What happens past it                                       |
| -------------------------------- | --------------------------------------------- | ----------- | ---------------------------------------------------------- |
| Single `PutObject`               | 5 GiB                                         | 5 GiB       | `400 EntityTooLarge`. Use a multipart upload.              |
| Multipart part size              | 5 MiB to 5 GiB (the last part can be smaller) | Same        | `400 EntityTooSmall` or `400 EntityTooLarge`               |
| Parts per upload                 | 3,000                                         | 10,000      | `400 InvalidArgument` on the part that crosses the limit   |
| Largest object                   | About 14.6 TiB (3,000 × 5 GiB)                | 50 TiB      | —                                                          |
| Object key length                | 958 bytes                                     | 1,024 bytes | Keys from 959 to 1,024 bytes fail with `500 InternalError` |
| Keys per `ListObjects` page      | 1,000                                         | 1,000       | `400 InvalidArgument` for `max-keys` above 1,000           |
| Keys per `DeleteObjects` request | 1,000                                         | 1,000       | `400 MalformedXML`                                         |
| Clock skew                       | Under 15 minutes                              | 15 minutes  | `401`                                                      |
| `Content-Length`                 | Required on uploads                           | Required    | `411 MissingContentLength`                                 |

Free trial accounts have a storage allowance. An upload that would take you past it is
refused with `400 EntityTooLarge` before any data is sent. The
[console](https://console.shelby.xyz) shows your usage.

## Choosing a part size

Because of the 3,000-part limit, your part size sets your largest file:

| Part size                         | Largest file  |
| --------------------------------- | ------------- |
| 8 MiB (AWS CLI and boto3 default) | About 23 GiB  |
| 64 MiB                            | About 187 GiB |
| 512 MiB                           | About 1.5 TiB |

rclone and DuckDB pick a part size for you when told the limit: `max_upload_parts=3000` in
the [rclone quickstart](/tools/s3-gateway/quickstarts/rclone), and
`s3_uploader_max_parts_per_file = 3000` in the
[DuckDB quickstart](/tools/s3-gateway/quickstarts/duckdb).

## What isn't limited

Objects stay until you delete them. Shelby has no lifecycle rules or automatic expiry.