Transformation Caching

Filestack allows you to cache your files in a user's browser by setting a cache control header in their HTTP response.

Note: The maximum accepted image size is 100,000,000 pixels. An image with this many pixels could have width and height combinations like 10,000 x 10,000 or 5,000 x 20,000, etc. There is also a file size restriction. Filestack will not convert an image that is larger than 256mb. Please contact us if you require the ability to process larger files than our current limits.

Cache Task URL Formats:[options]/[conversion task]=[options]/Filestack_FileLink_Handle
or<API_KEY>/cache=[options]/[conversion task]=[options]/File_URL

Can be abbreviated as e:31536000

Set the length in seconds to cache the file for. The N in this parameter is the number of seconds to cache the file in the user's browser for. - for example, cache=expiry:31536000 which will set the cache duration for 1 year. You can also use cache=expiry:max and the same value will be set for the cache headers: "Cache-Control:public, max-age=31536000".


Can be abbreviated as f

The cache can be set to false to ensure that you always receive a newly converted file. This setting is only recommended for testing purposes because every time a URL using cache=false loads, it will count against your conversion quota.

Cache Example

Here is a demonstration of the cache task in action:

screen capture demonstrating Filestack caching