> For the complete documentation index, see [llms.txt](https://developers.flipsnack.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.flipsnack.com/api-limitations.md).

# API limitations

Using our API, you can manage your publications just as you would in our online application. To ensure fair usage and stability of our infrastructure we have set a few limitations to this API.

**Note:** These limitations apply only to Flipsnack API and not the online application.

## Upload limitations

The number of uploads via the API is limited as follows:

|         | Enterprise                                                                                                                             |
| ------- | -------------------------------------------------------------------------------------------------------------------------------------- |
| Uploads | Max 1000 uploads per month.  This option is available only for Enterprise users when purchasing or upgrading to an Enterprise account. |
|         | **Important**: The limitation for the number of flipbooks in your workspace is also applied.                                           |

In case you exceed the number of uploads per month, the request will return the error code "32 - Uploads per month limit exceeded".

**Note:** Only successful upload requests from [`collection.create`](/api-reference/api-method-collection.create.md) are counted toward the monthly upload limitations.

## File limitations

The files uploaded via the API must be valid files of type PDF or JPG. You can make upload requests to create new flipbooks from PDF documents.

| Action            | Limitations                                                                                        |
| ----------------- | -------------------------------------------------------------------------------------------------- |
| collection.create | <ul><li>single PDF document</li><li>maximum file size: 500MB</li><li>maximum: 1000 pages</li></ul> |

You can upload a single PDF document using the `collection.create` API call. If you have multiple PDF files for a single flipbook, you should merge them into a single file and upload it.

## Request limitations

We limit Flipsnack API calls (both read and write) to a maximum of **5 calls per second** and **60 calls per minute** to ensure that system resources are distributed evenly. If you exceed the number of requests per second the API call will return the error code "31 - Requests per second limit exceeded".

We recommend spreading requests over a larger time period so you can avoid receiving this error.

Also, caching the request results on your side is strongly recommended.

## Error codes

Here are the error codes related to API limitations:

| Code | Message                                | Explanation                                                                                                                                                         |
| ---- | -------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 31   | Requests per second limit exceeded     | There were too many requests per second made with the same API key.                                                                                                 |
| 32   | Requests per minute limit exceeded     | There were too many requests per minute made with the same API key.                                                                                                 |
| 33   | Uploads per month exceeded             | You have exceeded the maximum number of uploads allowed per month.                                                                                                  |
| 34   | File size too large                    | The file you have uploaded has a size that exceeds the maximum allowed file size. For more information please see the limitations imposed by the API.               |
| 35   | Flipbook maximum pages number exceeded | You have uploaded a document that exceeds the maximum of 500 pages allowed. For more information please see the limitations imposed by the API.                     |
| 36   | Multiple files upload not allowed      | Flipsnack API allows only one file per upload request. Upload requests are made via the [collection.create](/api-reference/api-method-collection.create.md) method. |