[Support] uMatrix

I just published a release candidate with a fix for the <meta http-equiv="refresh" ...> in it:


See it this solves your blank page issue.

Yes it solves the issue with blocking acccounts.google.com. Now I see the login boxes as one should. Thanks for the quick fix.

Hi, simple question:

Days ago Gorhill mentioned he will prefer UMatrix for mobiles.
I am comfortable and can handle both, UMatrix and UBlock.

But, I don’t care at all about things like “hosts files”, “cosmetic filtering”, “popup blocker”, “zapper/picker element” etc etc etc.
I do care about RAM, system performance, firewall functions etc.
In this context, is there any reason to prefer UBlock rather than UMatrix?

I read a lot of stuff, but it is still confusing me the pros & cons of UMatrix vs UBlock.
Considering that I am not interested in ad-blocking functions, or anti-malware, or cosmetics, or hosts files etc, and considering that I focus only in “firewall functions” and system performance… am I right in choosing UMatrix rather than UBlock?

I understand that UBlock is more suitable for most of the users.
However, in my ignorance, a firewall function is many time better than any host file or cosmetic filtering etc. And the UMatrix friendly granular control avoids webpage breaking. I can block almost all the garbage with UMatrix without breaking pages. Why someone will prefer UBlock (less friendly granular control) with tons of hosts lists, filters etc, rather than a clean simple friendly strong firewall?
But Gorhill in the past two years seemed to be so passionate with UBlock, always arguing in favor of UBlock etc, that I have the feeling that I am missing something.
Every-time someone try to explain why to prefer UMatrix, Gorhill appears saying that the same could be done with UBlock in a kind of better and more efficient way. I can’t see that! What am I missing? Why to use UBlock rather than UMatrix? Which one is less system resources consumer?

Very odd issue with site breitbart.com

It loads very slowly (display takes an additional 3-4 seconds) vs instant

Here’s the rub. With Umatrix running, even when the site is unblocked, I have the issue

But If I run UBLOCK along side, the site loads and displays instantly.

So Ublock is doing something to speed things up that I cant get Umatrix to do. OR Umatrix is causing a problem, hard to tell.

Well I can no longer log in on the Discourse forum here, trying to log
in always errors :confused: So I have to reply through email, no idea how this
is going to be rendered on Mozilla Discourse.

So anyway… The issue is not the page loading slowly with uMatrix,
the issue is that the page hides it’s own content until some
conditions is triggered. uBO does not suffer this because it uses a
neutered script for googletagmanager.com, and this neutered script
contains code to prevent the delay in making the page visible.


But, I don’t care at all about things like “hosts files”,
“cosmetic filtering”, “popup blocker”, “zapper/picker element” etc
etc etc. I do care about RAM, system performance etc. In this
context, is there any reason to prefer UBlock rather than UMatrix?

No, you are definitely better off with uMatrix in such case.

I am back using uMatrix myself, hence why I am currently dedicating
more development efforts to it.

1 Like

@gorhill thank you for the answer, and millions thanks for UMatrix.

UMatrix is the best add-on ever.
Along the time, I compared UMatrix with almost all privacy/security add-ons over there. Of course these other add-ons have great features that UMatrix hasn’t (even UBlock has). But no add-on can beat UMatrix.
I also compared different UMatrix’ settings with lot of hosts files, rules, filters etc. and UMatrix alone, clean, minimalist, working just with the matrix and rules, it blocks at least 80% of the garbage without breaking 95% of the pages.

So, what can UMatrix improve?:

  1. Consuming less system resources, improving browsing performance.
  2. Adding security/privacy tools for the 20% unblocked web-traffic. Here it will be great to add some NoScript + ScriptSafe features to UMatrix, Also, APIs tools (from WebApiManager add-on) will be nice to add. And of course, some features from UBlock.
  3. It will be fantastic even more granularity, detailing items per domains/sub-domains (scripts etc).

I think about UMatrix as the most powerful firewall add-on in the market.
I understand the complementary function of hosts files, filters, popups etc. But a default UMatrix’ settings alone can block 80% of the garbage. So, the real focus should be to take care of the 20% web-traffic unblocked. And there, privacy/securities tools are more welcome in UMatrix, than hosts files, cosmetic filtering, popups etc. In place to go in UBlock direction, UMatrix needs to go in NoScript/SafeScript/WebApiManager etc direction. Less fruity cosmetic, and more strong security/privacy tools.

This is my personal opinion, and I take the opportunity to share with you.
I will be more than happy donating for this new UMatrix.
But, even if you can’t upgrade UMatrix… I always will be passionate for UMatrix.
Again @gorhill, millions thanks to your fantastic work!

Hmmm. so you’re saying because Umatrix doesn’t replace the script, there’s no way to avoid this delay?

Any other hack that might reduce the DISPLAY time at sites like breitbart?

Hi. I’m new to Discourse. Am I really supposed to make feature suggestions in a giant megathread like this?

Anyway, I’d like to suggest a tiny addition to uMatrix, namely being able to select fonts or graphics to represent the various blocking modes in the UI matrix, instead of just having colors (or colorblind friendly colors).

If fonts are for some reason not doable, how about border style in the matrix boxes? So that Allowed could be shown with a double dashed border, Blocked could use a 3px border, etc.

The problem with colors is that it becomes extremely difficult to use uMatrix in High Contrast mode (“Night Mode”) because all colors disappear.

I’m sure many people in the target userbase for uMatrix use High Contrast mode on a regular basis.

If you do decide to make this change and opt for graphical indication rather than user selectable fonts, please allow using bitmap graphics. Many people who use uMatrix probably are paranoid about security like me and disable SVG rendering in Firefox, because it has had security holes in the past. Also webfonts are not a good idea for the same reason.

I would just like to be able to see Allowed/Blocked indicated with Arial, Courier, Times, and the likes, instead of light green/green and pink/red.

I want to move from Windows as my every day driver to Ubuntu; so I wanted to know where my uMatrix data is stored? Can you tell me what file I need to move over? Thank you!

Just go in “About” pane and create a backup of your settings, you can then import these on the new installation.

Mine is currently stored in, using debian9 (Linux):


I’m sure there is a similar directory on Windblows where Firefox keeps it’s profile data

worker-src is not supported yet by Firefox, and the only way to block/report web workers is to use child-src. I know it is deprecated, but this is what works now for Firefox. Once it supports worker-src, I adjust the code accordingly.

Why not check for version to decide?
Or do you want your extension to ALWAYS walk behind the technologies?

Noticed that with a recent update there’s now a jigsaw puzzle in the popup panel, but doesn’t have a tooltip for what it is. What is it?

A few thoughts on uM (thanks for it, btw!):

  • When adding new icons/buttons, such as the recently added puzzle piece, I recommend doing so in a way that doesn’t shift others around if at all possible. After using this for the past few years, I’ve developed muscle memory for doing things, and I’m now constantly going to the wrong spot to click the lock/erase/refresh buttons since they’ve moved to the right a bit. Probably too late now to do anything about it in this case, but something to consider in the future.
  • After some discussion in this thread (the main discussion about this starts at this post), it seems a very useful ability you could add would be to whitelist domains for referers being sent TO the domain in addition to the current ability to whitelist referers coming FROM it, as well as the option to notify when it’s activated.
  • Another useful ability would be to be able to set spoofing rules, so it could be used to set certain sites (e.g. WSJ) to always be spoofed to look like google.com is the referer, which would allow it to take over the functionality provided by add-ons like Bypass Paywalls (as it is, until I realized the cause, I was often having content blocked from me due to this even if I was coming from google, since I use header spoofing, so a warning about that when enabling this might be a good idea).

Hi all, I’m rather new to uMatrix but I find it quite good.
I’ve learned something and could manage nearly all situation up to now.
I’ve a problem with couple of sites.
Usually, with a new site, I check what is not working, then I open the addon grid and found the disabled items (ping or red).
I then start to enable, one by one, what seems to make sense and try again.

There are anyway some website (a few) that with all enable are not working.
It happened today with a page on bondora.com and one on transferwise.com

On the first there are a couple of calendar icons that do not work at all,
on the second a chat icon with a circle (loading …) below that continue to rotate.

Both have the grid all red (where there are items) excluding googletagmanager.com and linkedin.com.
Both work if I open them in another browser (without a blocker).

My feeling is that there is some other domain involved that is not showed in the grid (neither in the umatrix register).

Am I correct and there is a way to see all domains involved in the page ?
Or do I miss something ?

BTW, with uMatrix I also use AdBlockPlus, HTTPSEverywhere and Privacy Badger.
I also tried to disable all of them but with same problem.


I’m running Win 10 using Firefox 63.0.1 64 bit and latest uMatrix. I don’t know why but the uMatrix icon is gone from the toolbar and I don’t know how to bring it back. Sites won’t load unless I disable uMatrix from in the add-on settings. I tried reinstalling the uMatrix add-on but that didnt help. How do I fix this please?

Just mentioning that for a longer period of time everything goes well with uMatrix. No problems, whatsoever.
Thanks, @gorhill, again!
Have a nice december! :wink:

I am currently using AdBlockPlus in addition to uMatrix (V1.3.16 on FF 63.0.3 Linux Mint), mainly for its ability to block certain annoying page elements on some websites.

Examples are from its filter list are:

Despite having spent considerable time on trying to figure out a filter rule to achieve the same effect with uMatrix’ “My Rules” alone, I didn’t succeed.

Hence now here my questions:
Can this be done?
And if so, how how exactly would the filter rule entry need to look like?

Thank you