Restore loading blue circle throbber in Firefox

Since Firefox 57 the loading icon has changed. Previously you’d see a blue circle spinning, now you see a dot moving horizontally. Personally, I prefer the old one.

So there’s this tip I found a while in the fantastic /r/FirefoxCSS Reddit, which restores the old throbber. Fortunately, Firefox developers kept the old animation file within the package, so we can still use them.

The following CSS must be added to “userChrome.css” file:

/* Revert tab throbber - for Nightly 57 as of 9/20/2017 */
.tab-throbber[busy]::before {
  background-image: url('chrome://global/skin/icons/loading.png') !important;
  animation: unset !important;
}
.tab-throbber[busy]:not([progress])::before {
  /* Grays the blue during "Connecting" state */
  filter: grayscale(100%);
}
@media (min-resolution: 2dppx) {
  .tab-throbber[busy]::before {
    background-image: url('chrome://global/skin/icons/loading@2x.png') !important;
  }
}

The “userChrome.css” is located in your Firefox profile folder. If it doesn’t exist, you can create it. Also, make sure it’s loading is enabled.