There has been a lot of discussion lately about the decline of the Firefox browser and numerous articles about it losing 50 Million users in the last two years.

But the real decline has been over 12 years with a total loss of half a Billion users and 75% of the market share it once held.

It all started in 2009 Q3 with the fateful decision to force…


As soon as this decision was made, Firefox starting losing market share. Every other program on a PC uses tabs against the active window. Proprietary software like MS Office and Adobe, FOSS software like Notepad++ and GIMP, 3D design, video editors, hex editors, you name it: It is the standard, logical design.

Then Google decided to make the tabs on top standard for its Chrome browser, which was designed for mobile devices not desktops. On a smartphone it may make sense, as there isn’t room for a full desktop style menu layout. On a desktop it is counterintuitive and breaks workflow with all other programs. The code for desktops is different from phones so there was no rational reason to try and force a mobile UI onto desktop users who were Firefox’s primary userbase. The argument that it was “too hard to maintain” a single setting enacted by 2 lines of code in a 4 Million line codebase is just insulting to the intelligence of users. Code isn’t a lawn. It doesn’t change if you leave it alone for a few weeks.

When inundated with user complaints about the change, the response I received from a lead developer who shall remain nameless was “We have hundreds of millions of users. 5000 people complaining doesn’t represent the majority of users”. Those complaints had one common sentiment, “If I wanted my browser to look like Chrome I’d just use Chrome”. And so they did.

Constant removal of features “that no-one uses”

Every change made to Firefox had the same pattern. The default feature was changed, but there was a menu setting to revert it. Then the menu setting was removed and you could only change it via about:config. Then the about:config option was removed. Every protest from the userbase met the same response “You’re just a tiny minority, most people like the change”.

75% is not a minority. Almost everyone hated the changes and each change pushed more users away, and the arrogant, condescending responses from Mozilla staff left a bitter taste in their mouth ensuring they would never return. Looking closely at the user numbers you could see a visible drop with every removal, only stabilising when a third party add-on or CSS would revert the change. Over and over, year after year. No lessons were learnt.

Removing settings wasn’t enough. Firefox went on to neuter add-ons and themes, forcing centralised signing and ultimately deprecating XUL without adequate webextension api’s to replace lost functionality. Complaining about this change I again spoke to one of the lead developers (same guy). His response was (exact quote) “People don’t use Firefox because of add-ons. Our telemetry shows 80% of users never install any add-ons” i.e. the telemetry that any tech savvy person immediately turns off because they don’t want their browser spying on them and about which we have also complained numerous times.

Even the one great move they made in UI design, the drag and drop customisable Australis interface, alienated more users because of the horrible default layout and lack of options that didn’t need CSS. The awful angled tabs (copied from chrome) is the only UI change Mozilla has admitted was terrible and they only did so, surprise surpise, AFTER chrome did away with them.

To this day, Mozilla still claims to want to hear from their users and after 12 years they still keep ignoring us, the awful default Proton UI being the latest foolish choice forced upon an unwilling userbase. (Type in “Firefox Proton” on Google to look at the most commonly searched suggestions if you think I’m in the minority). Fortunately it can still be mostly fixed with userChrome.css but even I’m getting sick of having to repeatedly patch together new code to keep up with constant deprecation and format changes.  

Bad coding paradigms

Mozilla’s source code is a nightmare. For example, default profile location is defined 3 times, using different variables, in 3 different languages, one of which is generated by combining multiple variables located in separate files. Another example I saw was another global variable being defined in 6 different files.

Post compiling, history for downloads, visited pages, bookmarks etc, are all shoved together into obfuscated files. The end result? Try deleting 400 entries from your history and watch how long it takes. Deleting that many lines from a separate text file would take a split second. Want to change the appearance of an icon or add a new one for a custom search? They’re mostly just PNGs, but they are obfuscated and sealed into the omni.ja file. Could otherwise be changed in seconds with your editor of choice, instead you need to install and learn a program like Eclipse and recompile the file with every change. The list goes on and on.

It is no wonder Mozilla’s coders have such trouble finding and fixing bugs. This led to an even worse coding paradigm, logging everything for the purpose of bugfixes. This is one of the culprits of…

Poor memory management

If a program is sitting there doing nothing, its memory usage should not change. Looking at my memory manager I have 40 processes obeying this principle. What is the only program constantly reading and writing to disk despite doing nothing? Firefox. It is running 13 processes and all of them are constantly doing both. I’ve been coding for 40 years and building PC’s for 30 so I do know a thing or two about how computing works. This is just awful design at the base level and no amount of tinkering on the surface will fix that.

The code paradigm is the root of Mozilla’s performance issues and they won’t address it. I’ll wager that’s also the reason for the failure of FirefoxOS, which was a great idea but failed because of poor execution and coding practices resulting in too many bugs to fix.  

Invading your privacy at the same time as telling us “we value your privacy”

Telemetry. Hidden telemetry that isn’t disabled when you click “disable telemetry”. Firstrun pings. Forced signing of add-ons. Auto-updates you can’t switch off, pinging every 10 minutes. “Experiments” which require a separate opt out. Now the latest offence is enforcing app based 2FA to login to a Firefox Add-on account just to make a custom theme, which you wouldn’t need in the first place if not for forced add-on signing.

Mozilla has as little respect for their users privacy as they do for our opinions.

Final thoughts

It didn’t have to be this way. It still doesn’t, but the mind that is incapable of admitting when it is wrong, or of considering differing opinions is doomed to stagnation and decay. The decision makers of Mozilla appear to have such minds so I do not hold out much hope for the future. Hopefully some of you out there can at least learn from their mistakes and succeed where they are failing. You succeed by giving users what they want, not telling them what they should want. By providing what is missing in the market, not blindly trying to copy your competitors.

The views and opinions expressed are those of the authors and do not necessarily reflect the official policy or position of It’s FOSS.

Author info: From Melbourne Australia, Dan has been coding for about 40 years and doing graphic design for 25 years. He also works on open source mechanical designs based on 3D printer kits.