Free Browser Extension that Efficiently Blocks Ads Using Less Memory


In response to a recent tip about a paid whitelist on a well-known ad blocker for Internet browsers, several readers recommended a different ad blocking extension called µBlock. Based on their recommendations and a discussion in our forum, I decided to try µBlock and I am glad I did. This is an extension definitely worth considering as a replacement for your current ad blocker.

Actually, it is more than an ad blocker. To quote the developer:

µBlock is not an ad blocker; it's a general-purpose blocker. µBlock blocks ads through its support of the Adblock Plus filter syntax. µBlock extends the syntax and is designed to work with custom rules and filters.

The extension is available for Chrome, Opera, Firefox, and Safari. Download links for the various browser versions are on the developer’s site here. I have tried it on Chrome and Firefox on Windows 8.1. Even with a fast system I find browsing with it to be noticeably quicker than with Adblock Plus, which I was previously using. If you have a slower CPU or a minimal amount of RAM, the effect should be substantial.

The extension comes with an extensive set of filters and can be used as is. However, there are a number of ways an advanced user can configure the settings, including adding many more filters. Information and discussion about using the extension are at the developer’s GitHub site. There is also a very informative wiki on the site at this link. Information about the various filters is here There is also a forum devoted to the extension at Wilders Security.

uBlock configurationWhen the extension is installed, a button is placed in the browser menu bar. Clicking the icon gives you the option to whitelist the page you are viewing. In the Chrome version, there is also a small eyedropper on the icon that gives the choice of selecting individual elements on the displayed page (example in the graphic on the right). More detail can be found here.

Configuring the settings can be done by the usual browser settings for configuring add-ons. In the Chrome browser, you can also right-click the µBlock menu icon to open a context menu. Select the entry “Options” and the menu shown in the graphic on the left opens.

Advanced settings such as dynamic filtering are available. This setting provides for the creation of rules for fine-grained filtering of particular sites. For example, all files of a particular type can be blocked from selected pages or rules can be constructed like “block 3rd-party frames of all origins". Most users will probably skip this advanced capability but the description of how it is done is here.

Which ad blocker, if any, to use is a personal choice but µBlock looks like a good addition to the general category.

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Please review/include Adguard Adblocker, which is highly configurable inclusive of your own whitelist. Thanks and regards. :)

I don't have any speed or lag issues with Adblock on my desktop PC but am glad that you mentioned uBlock (the "µ" is really pretentious and inconvenient) since my 2 Gig Chromebook needed some serious memory trimming. It definitely helped (as did removing other extensions that weren't really necessary on the chromebook). If anyone else has a similar problem, don't forget to turn off Offline Google Drive, a real memory hog.


It looks as the last several comments have been more critic than praise. Hence I feel that a different view might be valuable.

I am a non-sophisticated user, maybe like most of the users, and I have been very pleased with ublock since I installed it instead of Ad Blocker. It did not affect the speed of my browser [Comodo Dragon], and for the last couple of weeks I did not see even a single Ad. Earlier, with ABP I saw, infrequently, an Ad here or there.

Summary: UBlock works very well [at least for the last few weeks], it was trivial to install and use. Hence, it is appropriate to thank Vic laurie for presenting it to us.


I tested uBlock on a few sites against Adblock Edge that are notorious for advertisements, and Adblock Edge is better. Ads slip past uBlock that Adblock Edge stops.
You can add additional filters or rules.
Laurie it had the same basic filters: I loaded ublock on FF and went to It loaded up six tabs and an advert popped out. I then uninstalled uBlock and loaded Adblock Edge and did the same thing and no advertisements popped out.

I tested the site you linked to with default uBlock as the only extension that would block anything, and I didn't see a single advert or pop-up. Is it possible the program or filters have been updated since?

Are you sure that it was enabled/working (i.e. initially you need to click "update" to update the filters)? I find nothing out of the ordinary in browsing that site using the FF version.

I am sure it was working, going by another comment on this page; the problem may be related to multi tabs. I normally work with about 10-30 tabs open at all time.
The extension was originally written for Chrome and only later offered for Firefox. The FF version is still labeled beta and is not yet offered at the Mozilla repository. I have the impression that the FF version may not yet be as good at blocking as the Chrome version. I am using the extension mostly on Chrome so don't have much experience with it on FF. Thanks for relating your experience using it on FF. Anyone else have experience on FF where ads get through?

I have been using uBlock on PaleMoon (and Comodo Dragon) for about a month or two. I range thru a very large and varied number of sites, many of questionable probity. PaleMoon is configured for maximum privacy (Ghostery, etc) while Dragon is more permissive so as to allow commenting & social stuff to pass. Either generally have less than 15 tabs open at a time, but sometimes more.

Have not noticed any advertising getting past either. I have noticed some popup tabs opening at one site but I have not changed any of the uBlock defaults yet nor added any manual rules. Extra torrent shows no ads nor popups.

Interesting, I use PaleMoon (which I like very much) set to maximum privacy, Ghostery and uBlock and had popups in extratorrent on two different computers, one running win8 and the other running Vista. I switched it over to Adblock Edge, changed nothing and no popups.

Here are the extensions I have running in PaleMoon aside from uBlock; nothing all that special

Yes Extension BetterPrivacy 1.68
Yes Extension checkCompatibility 1.3
Yes Extension Classic Theme Restorer 1.2
Yes Extension ColorfulTabs 26.1
Yes Extension Extended Statusbar 1.5.8
Yes Extension Flash Control 1.1.1
Yes Extension Ghostery 5.4.1
Yes Extension ImageTools 1.0.7
Yes Extension LastPass 3.1.1
Yes Extension NoSquint 2.1.9
Yes Extension RightToClick 2.9.5
Yes Extension Tile Tabs 11.7
Yes Extension Vertical Toolbar 1.0.7

Neither PaleMoon nor Dragon show any ads nor popups at that url you posted. I do run a VPN but that should not make a dif. You have 3rd party cookies off ?

It could be one of my add-ons, but I am reluctant to get rid of any of them beside Adblock Edge does the job, I have not noticed any ads or slow down so I recon I will stick with it. PS Thanks for the tip about BetterPrivacy, it seems a good add on

Welcome. I change extensions like a model changes clothes ! Always something new to try out or get rid of and tastes / functions change. Got rid of classic theme restorer (buggy) and extended statusbar (taste) already but all of the security ones usually stick around.

You also should have a look at Comodo Dragon or one of their other variants. Always nice to have a Chromium browser version when a FireFox variant hiccups or chokes and Chrome itself is a pig.

I used to be like that too. I use Chrome and explorer only as a last resort browser, if all else fails so I use them with no addons. Here are some addons that I use that you might find useful Add to Search Bar 2.0 Double-click To Reload Tab 1.0.1 Duplicate This Tab 1.3 EagleGet 2.7 Fast Image Research 1.3 FEBE 8.3 MinimizeToTray revived (MinTrayR) 1.1.2 Places Maintenance 1.3 Selection Links 0.0.4

I tried it briefly but wasn't fond of it. It was a pain to find in the first place since AFAIK it's not listed among the FF official extensions page. Also, I prefer ABE because it shares ABP convenient (and effective) method of selecting a single element (image) to block which I often need.

I tried the element blocking in uB but didn't like it, it was confusing and often didn't do what I want.

So for the meantime I think I'll stick with ABE.

Why this add-on isn't listed on firefox add-on page? I really like to try this add-on but I don't like to have another thing to manage manually...

Because of my business I often have 25-50 tabs open at a time and have use either Adblock or Disconnect, depending on the sites. For the last few weeks I have been using ublock instead and it is great with a few tabs, but opening a lot of tabs and it is seriously slower than either Adblock or Disconnect. What I like about ublock is that I can use my custom Adblock filters.

article states: "In the Chrome version, there is also a small eyedropper ..."

that element picker is available in the FF version as well -- should be noted that for simple pick-and-click blocking however, it is very rudimentary and not nearly as polished as the Element Hiding Helper for Adblock Plus/Edge

also, the quickest way to open the config UI is to simply dbbl-click the title bar after clicking the uBlock tool-bar icon

lastly, for whatever reason, the dev is hesitant to add some necessary information in the UI when running in advanced mode -- for example, there is no distinction made between the 2nd and 3rd columns for blocking globally vs domain level. his logic is saving additional space, but the UI is a scrolling table so that's a moot point. in essence this is like like having 2 button on a GUI, both unlabeled, and you are supposed to remember which one does what :)

'The headline mentions "less memory" but there's no mention of that in the article...' @Jorpho, the article states this: 'If you have a slower CPU or a minimal amount of RAM, the effect should be substantial.'

So to quash and render irrelevant any all comments by those clearly not in the know with regard to this program and since I have been using it for several months now:

1) It is the best that I have ever used to-date as advertised as it requires MUCH LESS resources than AdBlock; and,

2) At minimum, just as effective as AdBlock in blocking ads since it in addition to other criteria, it uses the same block list as AdBlock.

Hands-down the best as of today, pure and simple.

PS: ...and hence why I love this Site so much and always ranks it at or near the top for any and all research that I do.

The headline mentions "less memory" but there's no mention of that in the article. What sort of performance improvement is there here?

(Personally I have no problem with people paying to circumvent AdBlock at the moment, but the day an auto-playing video ad or some variant of "1 tip of a flat belly" sneaks in, it is TOAST.)

The memory comparison can be found at the already cited wiki.

I also have noted an obvious improvement in both Comodo Dragon (a Chrome offshoot) and PaleMoon (a FireFox offshoot). [don't you love open-source?]

No problems whatever with either extension on any browser I use. Highly Recommended