Mozilla will remove the Developer Toolbar, also known as GLCI, from the Firefox web browser when it hits version 62 in September 2018.

Firefox users who run an earlier version of the web browser can display the Developer Toolbar with the shortcut Shift-F2 or by using the Tools menu.

The toolbar is quite handy for certain operations: you may use it to take screenshots, manage Firefox add-ons, change Firefox preferences, edit or remove cookies, or restart the web browser.

Basically, what it does is provide commands that Firefox users may run from the built-in command line. The fact that it is a command line interface makes it a tool for advanced Firefox users for the most part and developers.

Mozilla added the toolbar to Firefox in 2012 and it has been a part of Firefox since. The Developer Toolbar was not promoted much and that is one of the main reasons why it has not seen lots of usage.

The organization made the decision to remove the toolbar from Firefox based on the following reasons:

  • The user interface and GLCI is unmaintained.
  • Some features are broken because of Firefox's multi-process architecture e10s.
  • Low usage.
  • Alternatives are available.
  • The feature blocks UnsafeSetInnerHTML.


The main tracking bug on Bugzilla provides additional information. Mozilla plans to remove the Developer Toolbar and browser references in Firefox 62. Firefox 62 Nightly does not support the Shift-F2 shortcut already; nothing happens when you activate it.

As far as alternatives are concerned:

  • Screenshots -- Mozilla suggests to use Firefox's screenshot tool instead which the browser ships with. It does not support some operations right now though such as capturing full page screenshots or setting a device pixel ratio.
  • Restart -- load about:profiles, click on the restart button, or use operating system specific options such as Alt-F4 on Windows or Cmd-Q on Mac, and loading Firefox anew afterward. Also possible to use Ctrl-Alt-R in Developer Tools but only in Nightly.

Mozilla revealed that restart is by far the most used command that users run when they use the Developer Toolbar.

Closing Words

I have to admit that I did not use the Developer Toolbar much but it was quite handy for restarting Firefox quickly (Shift-F2, type res, hit tab to auto-complete to restart, hit Return).

The removal may be a loss to some who use it for the same purpose or other purposes. I think that Mozilla should have alternatives for the most used actions in place and communicated to Firefox's user base before the feature is removed from Firefox Stable.