浏览器如何删除不再使用的本地存储？

Question

According to MDN a web page's local storage is kept by the browser itself.

1. How does the browser associate a web page with the page's allocated local storage?

   I wrote a web page that uses local storage for personal use. In development I have multiple versions that all added to local storage.

   If I delete a web page that employs local storage then how does the browser know to delete the local storage for that web page?

2. (My main question) I am worried that local storage kept by a browser will continue to grow and grow if I repeatedly delete web pages that employ local storage.

Answer 1

Local storage is stored in relation to the calling web page's domain, not individual pages. So adding to local storage via foo.com/a , foo.com/b and foo.com/c will all contribute to the browser's allocation for foo.com .

The browser deletes localStorage data when requested by the calling page, or when cleared out manually by the user. Unlike cookies or sessions localStorage does not automatically expire data. So scripts using localStorage should tidy up after themselves where possible, and watch out for hitting the allowed limit (for example using try/catch to avoid an QUOTA_EXCEEDED_ERR exception when using localStorage.setItem ).

Answer 2

Thanks Graham! From perusing Stack Overflow, Ctrl-Shift-i will bring up local storage information on the current web page's domain. What I discovered is that local web pages I create myself on my computer all have the domain name "file://".

Since all local web applications I create on my computer have the same domain name, clearing local storage from one is bad because it clears it from all the others. This means that different applications shouldn't use the say keys and that each application should clear its own keys rather than the entire local storage. Anyway you were dead on.