I-Firefox Community Forum

About once a minute or more Firefox lag by 10-15 seconds before showing a character or characters I have typed.

It seems to be using a lot RAM. I have one window open with six tabs, including this one, and it is using nearly 8GB. There are 48 processes showing in Activity monitor.

I am using version 135 on a Mac Book Pro running MacOS 15.3 (Sequoia).

It is almost unusable.

I have gone into about:config and changed all the telemetry entries et al to false to prevent as much datareporting as possible - what I want to do is prevent Firefox (135) from creating the 'datareprting' folder in my profile folder. I delete it every time I go into Firefox, which is an everyday pain because it returns with EVERY new session. I delete it 1. because they don't need it, and 2. more importantly, firefox is NOTICEABLY faster once it is deleted. People have been asking this since like FF 40. Can anyone solve this?

I am on a Mac desktop running Ventura 13.7.3 and running Firefox 135 with extension of Ghostery, Privacy Badger, Google Don't Track Me, Facebook Container, FoxClocks and SoftGreenLeaves theme. All of these extensions have been playing nicely with each other for a long time.

Recently I've been having trouble recently with Firefox doing that thing of suddenly freezing/producing multiple windows and I need to refresh in order to get it working properly again. This has happened three times in the last five days - so frequently that I now keep the refresh instructions on my desktop. Today I heard the CPU grinding and clicked open my Activity Monitor to see four listings of 'FirefoxCP Isolated Web Content' running all of them using in excess of 2Gb. Unfortunately I wasn't able to get a screenshot of the Activity Monitor while this was going on as I had the Mac force quite Firefox and the moment I did, the activity stopped, but I've attached an example of the Activity Monitor showing still high CPU values for a few moments of browsing.

So what's up? How can I stop the CPU grab? How can I stop the frequent crashing?

There is a similar (but not identical) topic on Mozilla Connect , and I posted there. But I did not get a response. So I am re-posting on this new topic on Mozilla Support. I have a similar problem to what was discussed on Connect. I am using Firefox 133.0.3 on Windows 10 Professional. After Firefox has been running for a while, I get a message from Windows 10 that the free space on my C:drive is low. I did a directory listing on my C-drive before and after Exiting Firefox; I saw no large files disappearing. Then I decided to do "dir c:\ /ah" to see hidden files. What I saw was that pagefile.sys decreased in size from 29,925,748,736 to 16,270,770,176. This was a decrease of 13.7 Gb. Is this normal? I have lots of windows and tabs open in Firefox. Thanks.

If Mozilla is going to add an annoying left side scroll bar they should also include a facility to disable it. I don't use the right side scroll bar, I certainly don't need another not to use. Besides it interferes with some websites....

Help

I followed the instructions to install flatpak and then firefox (from the Mozilla pages) and got to the end, but Firefox was not not the path. There was a shell script in/home/edg/.local/share/flatpak/app/org.mozilla.firefox/x86_64/stable/869b4e0279ab4475432b2930ae5d583b7a0e00bac1078b8848d163820a152fa5/files/bin/firefox but it led to /app/lib/firefox/firefox. The /app directory doesn't exist.

Not sure what is wrong.

I have no organization.... why is this at the top of my settings and how do I get rid of it

also how do I get more shortcuts on the main home screen.... I checked 4 rows and it only shows 1 and one half row

I upgraded to Firefox 135.0 the other day and tried it out on a site I have used several times a week for at least 10 years. A .csv file that I regularly download failed to do so. The system simply failed to respond, and nothing appeared in the download window. The site offers the option of downloading the same data in a .xls file, and that worked. (My previous, obsolete, Firefox gave me the option of where to download to, and remembered the choice between vists. Such is progress!)

I'm using Firefox in a kiosk-mode application, on a Raspberry Pi based system, started from a bash script like this:

# Clear history etc. to prevent problems if unit is not perfectly shut down rm -v -r /home/pi/.mozilla/firefox/*.default rm -v -r /home/pi/.mozilla/firefox/*.default-esr rm -v -r /home/pi/.cache/mozilla/firefox/*.default rm -v /home/pi/.mozilla/firefox/profiles.ini

sleep 2

/usr/bin/firefox-esr --kiosk -url http://127.0.0.1

However on booting I get a banner from Mozilla along the top of the screen saying: "Firefox automatically sends some data to Mozilla so that we can improve your experience [Choose what I share]"

This is not acceptable in kiosk mode, as it would give users access to the configuration as well as being a visual annoyance. How can we disable this?

Hello Mozilla Community,

I’m currently using Firefox for my web design projects and facing some performance issues when testing websites built with modern frameworks. As a developer at DE IT SOLUTION where we provide website design and development services, I rely on Firefox for testing due to its robust developer tools.

However, I’ve noticed:

Firefox becomes slow when handling multiple tabs with live previews. Developer Tools sometimes lag during real-time CSS adjustments. I would love advice on:

Best practices for optimizing Firefox for web development. Recommended extensions that won’t slow down the browser. Tweaks for faster rendering of web pages during testing. I’ve explored Mozilla’s tips but would appreciate insights from this expert community. Also, if you’re interested in how UX/UI impacts web performance, you might enjoy this article from my experience: Why UX/UI Design Matters in Web Development (Sharing for learning purposes).

Thank you in advance for your suggestions!