Add-ons extend Firefox’s functionality, making it one of the most extensible browsers available.
Add-ons are third-party creations that in some cases have contained malicious code, so install only those from sources you trust. Additionally, too many add-ons or even a single poorly written one can bring Firefox to its knees, so promptly uninstall any you do not need.
When selecting an add-on, I look for one that:
- is open source and multiplatform
- is actively maintained
- has active support, whether by developers or users
- has a good security record
- does not noticeably affect Firefox’s performance
To install an add-on, use Firefox to browse the repository.
SECURITY AND PRIVACY
- Adblock Plus is an advertising blocker. Open source.
- Ghostery is a behavioral advertising blocker.
- HTTPS Everywhere encrypts your connections to supported websites by rewriting all requests to these sites to HTTPS. Open source.
INTERFACE AND USABILITY
- Flash Video Downloader downloads videos from YouTube and other supported sites and converts them to your preferred format. After each update you are taken to the DownloadHelper website; this behavior apparently cannot be disabled. TODO: Find an open source equivalent.
- Open in Chrome adds “open current tab in Google Chrome” to the right click context menu. Also works with Chromium, the open source parent of Chrome. What I do is use Firefox (secure, locked down) as my daily driver, and have Chromium (with out of the box settings) as a backup. When I encounter a page with display issues in Firefox that might be due to my too-high security settings, I use this add-on to easily open the page in Chromium and take action depending on what I see there.
- Spellcheck dictionaries in different languages. Be careful: it’s easy to accidentally select a language pack instead of a dictionary. License varies by dictionary.
- Tab Groups replicates the Panorama (aka tab groups) feature removed from Firefox 45.
- MeasureIt draws a ruler across any web page to check the width, height, or alignment of page elements. Open source.
- SeoQuake provides data useful for search engine optimization and web site promotion. Open source. After each update you are taken to the SeoQuake website; this behavior apparently cannot be disabled.
EXTENSIONS I’D LIKE TO SEE
My add-on wish list includes (reader comments wanted):
- An extension to password protect access to Firefox’s preferences, useful for public kiosks where users tend to mess around with such things.
- A phishing site blocker similar to PhishTank that works on modern versions of Firefox. There’s the Netcraft antiphishing toolbar, but I dislike how much space it needlessly occupies.
INTERESTING LOOKING EXTENSIONS TO TRY
These notes were last updated 6 February 2016 with reference to the soon to be released Firefox 45.