HTML5 offline applications, how long can they be stored if not visited?

Question

I was looking at Offline Web Applications using an HTML5 Cache Manifest.

Just wondering, if a user visits the application, and the resources are immediately downloaded for offline use, will they ever be deleted? (without user intervention such as Clear Browsing Data)

For example, someone visits my site, which has several somewhat sizable jpeg files that are used as wallpaper options for my webapp... but he/she may never visit my site again? How long do the offline files last when using a Cache Manifest?

Answer 1

It can be deleted or updated by itself, until the user does something with the manifest file.

Once an application is cached, it remains cached until one of the following happens:

• The user clears the browser's cache
• The manifest file is modified
• The application cache is programmatically updated.