RefToolbar refers to a series of JavaScript/jQuery scripts that help editors add citation templates to articles. It works in conjunction with the MediaWiki extension WikiEditor. The Reftoolbar implementation is scattered across several scripts (see, for example, this, this or this prefix search). The newest version, RefToolbar 2.0 is turned on by default for new users.

Originally an opt-in Wikipedia Gadget, Reftoolbar was moved to a site-wide script on February 25, 2011, and to an opt-out gadget on April 2014.[1][2] It comes in two versions, depending on the settings at Preferences → Editing → Editor.

Click on the version number for more information about each refToolbar implementation.

Table headings are abbreviations of the names seen at Preferences → Editing:

The RefToolbar style column indicates the widget that activates the cite mechanism.

Before 2017, there were three versions of Refoolbar: 1.0, 2.0a and 2.0b. Version 2.0a was removed on June 14, 2017, since it was no longer needed.

Then you are using the rich-text visual editor. It also has a Cite button, with an auto-filling citoid service, but that one is NOT RefToolbar. If you want to learn how to use that Cite menu, please refer to the Visual Editor user guide.

You can also do a "subpages with prefix searches" to find other related pages, in particular MediaWiki and Wikipedia namespace searches are useful.