Two new capabilities are being released in tandem with Firefox Quantum, the latest version of the browser. There is now an extensions button in the browser, and MV3 extension support is enabled by default. Mozilla, the creators of Firefox, think these updates improve privacy and make it easier for extension developers to work across browsers. No need to worry about your ad blocker, though; add-ons that disable advertisements will continue to function normally.
Aside from MV3 compatibility, which is mostly an under-the-hood update, the most noticeable change is the addition of an extensions button to the toolbar. This new button, inspired by Google Chrome and Microsoft Edge, allows you to manage your extensions from the same location. The jigsaw puzzle symbol on the toolbar will take you to the new button. Keep in mind that you may not find an extension that you’ve previously bookmarked to the toolbar in this new panel. Because an MV3 version of certain add-ons may not be readily accessible, this menu may also lack controls for such add-ons. The larger purpose is to aid in the management of extension access rights on sites.
If you haven’t heard of MV3, it’s an extension standard suggested by Google a while back. But many were concerned that it may restrict or otherwise affect ad-blocking software. Firefox’s decision to add MV3 compatibility is a move in anticipation of the inevitable once Google finally makes the transfer from the existing Manifest Version 2 (MV2) standard to the new MV3 standard in Chrome. This is done so that programmers don’t have to worry about supporting varying extension versions (MV2 and MV3). This aids compatibility, but Firefox also claims to have made other improvements to keep privacy-protecting add-ons like uBlock Origin and ad blockers running smoothly. Further, MV2 extensions will continue to work and be supported in Firefox.