Browser Extensions for Firefox

Browser extensions are add-on programs that can perform a wide range of actions. Most extensions are written by individuals or other companies, not Mozilla. A few are chosen as "Recommended" extensions and carefully reviewed, while others are analyzed by software and from time to time a small team of human reviewers. You should only install extensions you feel comfortable with after considering their potential value to you, what access they have to your browser data, and whether the author looks trustworthy. It's not always an easy decision!


Firefox is far from perfect, and from time to time you need a hand to work efficiently. These extensions are aimed at solving specific problem that afflict many Firefox users. For problems with user interface styling, you could dive into the world of overriding user interface styles over on

Content-Type Fixer (AMO Listing)

When Firefox receives a download, it doesn't guess what type of file it is, it relies on the server to send the proper Content-Type header. Some servers do not send helpful information. This extension lets you repair or override the Content-Type header. It also allows overriding the Content-Disposition header, which can force downloading and bypass your normal instructions. More details on the Content-Type Fixer page.

Printable – The Print Doctor (AMO Listing)

Firefox doesn't always "paginate" correctly. Some style rules are interpreted as creating an unbreakable block of content which will run off the bottom of the page. This and other annoyances are tackled by this extension. More details on the Printable page.

Cache Favicons for Bookmarks (AMO Listing)

Firefox doesn't save the site icon for bookmarks if the server forbids caching them. There are other reasons Firefox might not save the icon that this can't fix, but if the generic globe really bugs you, you can give this one a try.

Outlook Mail - mailto and Email Link Fix (AMO Listing)

Firefox doesn't include a built-in connector between an email address link and Outlook online (whether on or This extension helps fill the gap.

Yahoo Mail - mailto and Email Link Fix (AMO Listing)

Yahoo doesn't like the format of information sent by Firefox when composing a new message. This extension helps fill the gap.

Image Info and WebP Conversion/Avoidance

Firefox doesn't have a built-in option to convert WebP images to more conventional formats when saving, and Firefox 87.0 removed View Image Info from the right-click context menu. These extensions address these issues.

Save webP as PNG or JPEG (Converter) (AMO Listing)

This extension uses an HTML canvas to offer multiple choices of formats, and supports automatic saving and additional file name options. It also has a basic image info panel.

Don't "Accept" image/webp (AMO Listing)

This extension removes image/webp from the list of formats Firefox tells sites that it accepts. That should discourage many servers from replacing JPEG, PNG, and animated GIF images with WebP images. (But some may send webP anyway; it isn't blocked.)

View Image Info Reborn (AMO Listing)

Firefox 87.0 removed View Image Info... from the right-click context menu, which makes it less convenient to open the Page Info dialog, Media panel, to the correct image. This extension generates its own Image Info window, and offers Save As... Options that incorporate the core functionality of the previous two extensions to ease saving of WebP images.

General Purpose Extensions

Switch To Previous Active Tab & Reload All Tabs (AMO Listing)

Provides a button and keyboard shortcut to switch to the previous active tab in the same window, or in any window, as well as view a list of recently active tabs in the same window and across windows. Also has the option to restore the "Reload All Tabs" command to the right-click tab context menu.

Show History Frequent Sites Button (AMO Listing)

One of the changes in the redesigned address bar in Firefox 75 was to remove the old "Show History" button that listed frequently visited sites in the drop-down. This extension creates a button outside the bar to show a list that is more similar to the old one than the Top Sites section of the new tab page.

Special Purpose Extensions

Every now and then I create an extension on request that I don't use myself.

I Hate Tabs - SDI for Firefox (AMO Listing)

Do you prefer every page to open in its own window? This extension is for you.

Ctrl + Shift + C Should Copy (AMO Listing)

If you habitually use Ctrl+Shift+C to copy text, it's probably endlessly annoying to have Firefox's Page Inspector tool open. This extension injects an override script into pages to take back that keyboard shortcut.

Prevent Closing Window (AMO Listing)

This extension lets you add a tab to a private or regular window that prevents accidentally closing the window without your specific approval. A little buggy, though, you may get extra tabs.

Move Active Tab to Last (AMO Listing)

Let's say you want a tab to move to the right end of the bar every time you activate it. Join the three users of this extension.