Chrome Ad Blockers: AdThwart Vs. AdBlock , Round 1

One of the most important aspects of a web browser today is how good it is at blocking ads. Users thinking about switching to Chrome from Firefox NEED to have a reliable ad blocker. The two best ad blockers are AdThwart and AdBlock. They both support EasyList, but that doesn’t mean they are both equally effective and user friendly.

UPDATED: 1.25.2010 UPDATE #2

One of the most important aspects of a web browser today is how good it is at blocking ads.  Today Google announced that it has released a Windows version that has the ability to use extensions.  This means that extensions are ready for the masses.

Users thinking about switching to Chrome from Firefox NEED to have a reliable ad blocker.  The two best ad hidders are AdThwart and AdBlock.  I call them ad hidders because currently Chrome is unable to block ads the way we are accustomed to seeing with Firefox.  Until Chrome developers add this functionality, these two extensions are forced to simply edit the CSS on the fly.  They both support EasyList, but that doesn’t mean they are both equally effective and user friendly.  I decided to compare a vareity of categories that I look for in an ad blocker.

Have a look at my chart below which goes into detail about each extension

AdThwart vs AdBlock

The winner is AdThwart!

Both produce similar speed results, both are maintained and updated on a near daily basis, both have a wide user base, both hide most ads, both have friendly and bright developers working on them.

AdBlock has issues with it’s icon to show if a site is blocked or not.   The icon is actually a separate extension, so if you disable AdBlock, the icon remains.  That is a glaring issue for ease of use.  I also have no idea how to edit the custom filters I applied, what happens if I end up blocking all images by accident?  Those of you who care about open source, AdBlock is not entirely clear on the subject, whereas AdThwart is open source.

The issue of speed I want to touch on in more detail.  At first glance, the speed tests seem to be inconsistent when it comes to speed of a page with no extensions applied.  TechCrunch takes a lot longer to load when advertisements are present, but MSN is much quicker when ads are present.  How can this be you ask?  Well, it depends on the type of advertisements on the site.  MSN has ads that don’t require the browser to render them as much as TechCrunch, therefore when we add the added time it takes for the extensions to hide the ads. . . it actually takes longer to load.  However, I am pleased to see in testing that for the majority of websites, hiding ads does make load times faster.  The fact that AdThwart is a tiny bit faster may not mean much because it is probably not even noticeable.

I also want to mention that each page load could have different ads, sometimes it would include an image ad, other times an it would have a javascript ad.  Other times the sever may have a slower response time than the previous request.  Therefore the speed tests can vary greatly.  To combat that, I reloaded each page 5 times and took the average.  I’m looking to compare rendering speed and the response time for the server can screw that up.  Any time the server responded with a response time of over 500ms, I redid the test.  I performed each test using Chrome’s developer tools resource tracking (Ctrl+Shift+I).

So where does this test leave us?  AdBlock needs to go back to the drawing board for the icon implementation, provide more details on if the extension is open source or not, and revamp custom filters.  The majority of users should be more pleased with AdThwart’s ease of use and custom filter implementation.

9 replies on “Chrome Ad Blockers: AdThwart Vs. AdBlock , Round 1”

As Chrome doesn't have Content Policy yet, and can't actually block ads before they load, these are in fact page element hiders. They do a great job though, considering what's missing from Chrome at present.

The best way is to use a local proxy application like BFilter, Proxomitron or Privoxy. Then use one of these extensions to clean up page elements you don't like. Sorted!

From a technical point of view I prefer Adblock too. But on the other hand, Adthwart seems to be open source, with a public repository on Github, while you cannot find that much information about Adblock – it's not even possible to find a license of something like this. That's my number one reason, why I'm still using Adtwhart.


This is Michael, the AdBlock developer. You're the first person to compare these two ad blockers — well done!

I am actually an hour or two away from releasing a new version with an optional browser action icon, which actually lives by the Wrench instead of within the address bar as AdThwart does. It will allow blacklisting and whitelisting without using keyboard shortcuts, for those who prefer that approach. I hope you'll update your post at that point! 🙂

Thanks for checking out the review Michael. Just trying to do my part. 🙂

I will keep an eye out for the new release and update my review. AdThwart also just added the ability to block in-text ads, so it should be interesting to see who comes out on top.

I'll be sure to do more pagespeed tests as well because that is a key point.

Thanks again for the feedback, Brant!
– yes, it's open source — but I need to put a license file in place. While anyone can access the source once they install the extension, I'll be putting it up on Google Code shortly.
– The button does need to notify you if you uninstalled AdBlock and left the button in place — it will tell you to right click it and choose Uninstall which will remove it completely.
– Your confusion about how to edit a blocked ad is a great point! I'll add a link to the end of the blacklist wizard, pointing you to the Options page (where you can manually add/replace/remove filters.)

You're doing the community a service with these posts — keep 'em coming!

– Michael

Ability to block ads gives to Chrome little chance to compete with such well made browsers as Opera and Firefox. But it still remain one of 'better than IE'. There is at least one up to date browser which not better?

I use Ad Muncher, Best Ad Blocker out there!

Blocks ads in all browsers, including Internet Explorer, Firefox, Opera, Google Chrome, Safari, Flock, Netscape, Maxthon and Avant Browser, blocks many spyware, adware and dialer installers, have a lot of functions and daily filter list updates, it is a lot much better than any ad blocker.

It's not free but definitely worth the money.

Now Adblock Plus (the equivalent to the Firefox one) is available for Chrome:

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