1/8/2018 - 2:29 AM


Deprecated!   Use Service Workers or Cache API instead.
Why service workers are better

Creating HTML5 Offline Web Applications
Common Appcache pitfalls also:

  • mime type config in servers

Specifying a whole folder of files won't cache every file, only those loaded.

If clearing cache in Firefox doesn't work, then also clearing Site Data under Options -> Privacy & Security might work.

Access cache in Firefox: about:cache


  • cache clear doesn't always work at first (eg console might show that 'css' (folder) fetch failed, even tho the erroneous line was removed and cache cleared)
  • while offline, browser (chrome, firefox) refresh might result in page load error yet if the page is opened in a new tab, it loads just fine - seems to result from a faulty cache
  • any mistakes in appcache will halt it being read further (at least in firefox)
  • maybe some problems have to do with keeping multiple tabs of the website open
  • to force cache manifest to update, add or remove a comment
  • after going offline, it can take a long time (15 seconds) for the cache to kick in...
  • testing in localhost doesnt work