Bug #84

The browser never completely clears the cache

Added by my self almost 5 years ago. Updated almost 3 years ago.

Next Release
Start date:
Due date:
% Done:


Estimated time:


Hello, I discovered a strange behaviour concerning the cache clean-up mechanism. Steps:

  1. Do a fresh install of Privacy Browser and start it
  2. Open settings, check "Enable JavaScript by default" and change the User agent to "Firefox 48 on Android 6.0.1"
  3. Go to and wait for the page to load (tap on the shield to enable JavaScript if the page won't load)
  4. Bookmark the page for convenience
  5. Now, disconnect the device from the Internet: Wi-Fi, mobile data and everything. Go offline.
  6. Close the browser using "Clear and Exit"
  7. Through Android settings, force close Privacy Browser. Clear the Cache and reboot the device if you want
  8. Restart Privacy Browser and open the previously created bookmark

A ghost of the Twitter website will show up, with icons, buttons and cookie bar. From where it came from? Why the browser does not simply show an error saying that there is no Internet and so it can't load the URL?

I think the culprit here is the WebView, and maybe... IndexedDB or similar? The only way I found to delete that strange cache, is to clear all the Privacy Browser data through Android settings. Other WebView based browsers do the same thing (Lightning). Can you investigate on this? Thanks!



Updated by Soren Stoutner almost 5 years ago

The data is stored in:

/data/data/com.stoutner.privacybrowser.standard/app_webview/Service Worker/CacheStorage/


Updated by Soren Stoutner almost 5 years ago

There appears to be no way to delete these cached files. A bug report has been filed with Google:


Updated by Soren Stoutner almost 5 years ago

  • Status changed from New to In Progress

Updated by Soren Stoutner almost 5 years ago

  • Status changed from In Progress to Closed

It turns out we can manually delete the entire `app_webview` folder on `Clear and Exit`. This is a nice solution because it gets rid of a bunch of cruft `WebView` leaves lying around.

Fixed in commit;a=commitdiff;h=4474c3d7c1c831fa46a3bfc17056bbd87ecacb9f.


Updated by Soren Stoutner almost 3 years ago

  • Priority changed from 2 to Next Release

Also available in: Atom PDF