Blocking website adverts in web browsers has been a hot topic in recent years and there are merits to both sides of the argument. Many sites out there bombard you with tons of ads, and quite often you will feel that you have no choice but to use an ad blocker because either the ads slow down the site loading too much, or they are incredibly annoying and get in the way or distract from your browsing.
On the other side, there are sites that try to inconvenience you as little as possible and be sensible with the amount of ads displayed and their placement. Blanket use of ad blockers will hurt those sites just as much as the bad sites you feel have gone overboard with their ads. It’s no secret the vast majority of websites on the internet need to use ads to help pay for running costs. Staff, hardware, fast servers, fast CDNs and the like are not free and need to be paid for.
But we cannot get away from the fact an ad blocker is probably the number one add-on for browsers like Chrome and Firefox, and will continue to be so for some time yet. Besides removing the adverts, ad blockers also save bandwidth by cutting down the amount of content a page loads, they can also help with your privacy by blocking scripts that track your browsing habits. There’s several ad blocking extensions available for Chrome and Firefox, and some work better than others. To see what they do when when loading a web page, we’ve decided to put a number of ad blockers to the test. This test is about the performance of an ad blocker in terms of how quickly it loads a range of ad blocked pages, the maximum amount of memory it uses and how much stress it puts on the CPU.
The Ad Blockers on Test
There are many more ad blockers available in Chrome than in Firefox which is the reverse of what we expected. Here are the ones we are testing for both browsers.
AdBlock for Chrome – The most popular ad blocker for Chrome with reportedly over 200 million downloads. There was a Firefox version released briefly but that was pulled from the Firefox add on pages for unknown reasons. AdBlock has acceptable ad options for YouTube and Google search but they are off by default.
AdBlock Plus for Chrome/AdBlock Plus for Firefox – One of the most well known ad blockers and also one of the most controversial because AdBlock Plus started off the trend of introducing acceptable ad whitelists. The AdBlock Plus website also has versions for Opera, Safari, Maxthon, Internet Explorer and even Android.
AdBlock Pro for Chrome – AdBlock Pro is based on AdBlock Plus but has a simpler options interface and no acceptable ads option. The icon button sits in the address bar instead of the normal add on area and has 3 simple options to disable, go to options or create a filter.
Adguard for Chrome/Adguard for Firefox – Adguard is easy to use and extra blocking scripts can easily be added. Adguard’s main product is a shareware desktop application that blocks ads in a number of browsers without the need for browser add-ons. Beta versions of both add-ons are available for testers.
AdRemover for Chrome – AdRemover is based on AdBlock with just about the same number of options minus the support tab. On the face of it, most of the differences appear to be cosmetic and although it doesn’t ask for donations, there are social media buttons when clicking the icon.
Ghostery for Chrome/Ghostery for Firefox – Ghostery can block analytic scripts, widgets, web beacons, privacy scripts and or course advertisements. The good thing about Ghostery is the ability to individually enable or disable scripts on a per site basis. Versions are available for Opera, IE, Safari and mobile operating systems.
Simply Block Ads! for Chrome – This hasn’t been updated since 2014 and there’s reports that some ads aren’t being blocked, but it blocked all ads on our test sites so we included it. Simply Block Ads! (aka Simple Adblock) is the easiest to use and the only option is an opt-in to send usage statistics.
SuperBlock AdBlocker for Chrome – This is another AdBlock fork and appears to be by the same developer as AdRemover. Apart from an extra entry in the filter list and a few styling changes, we can’t see much difference between the two, perhaps there are more changes underneath.
µ Adblock for Firefox – µ Adblock (Micro Adblock) is Easylist and EasyPrivacy based, and almost as easy as it gets. Simply click the icon to block/unblock specific sites. There are only 3 options including blocking social buttons. One issue is µ Adblock hasn’t been updated since January 2015.
µBlock Origin for Chrome/µBlock Origin for Firefox – An up and coming ad and script blocker for both Chrome and Firefox, it also claims to be very CPU and memory efficient. A lot but not too many scripts are blocked out of the box and it’s easy to use with a number of other blocklists readily available. You can also allow or block specific sites from loading on the page via advanced mode.
Ad Blockers not tested
AdBlock Edge (Firefox) – The project has now been discontinued and the author recommends µBlock Origin instead.
AdvertBan (Firefox) – Hasn’t been updated since 2012 and inevitably leaves most or all ads untouched.
AdBlock Lite (Chrome and Firefox) – Left a number of ads untouched on our test sites, even in the more aggressive Full mode. Various sources say the project has all but been abandoned.
AdBlock Super (Chrome) – After reading reviews and doing some testing we found that this addon actually injects ads of its own from a number of third parties. At best it’s adware, at worst it’s malware and should be avoided at all costs. Below are highlighted ads we received when visiting Amazon.com.
µBlock (Chrome and Firefox) – This version is essentially a clone of the original µBlock which was later renamed µBlock Origin. The author of µBlock Origin, Raymond Hill, has since disassociated himself from the µBlock branch and no longer contributes to the project. For these reasons we will test only µBlock Origin.
How We Tested the Ad Blockers
Testing websites can be tricky because ads are served by third parties so a page is depending on external servers during loading. To try and even out any inconsistencies and also any differences with other servers being used by the website, each webpage tested was refreshed 10 times in succession and any times considered abnormal were discarded and the page refreshed again. Then we looked at 3 different scores:
Page load time – An average taken for the page to load 10 times. We are using the Load event to time when the browser has finished retrieving all the resources required by the page. In Chrome this is a red score on the Network tab in Developer Tools. Caching is disabled so resources are refreshed each time.
Peak memory usage – We watched the memory usage of the ad blocker’s process in the Chrome Task Manager (Shift+Esc), the maximum amount of Megabytes used during the 10 page loads was recorded.
Peak CPU usage – Similar to memory usage, using the Chrome Task Manager the maximum percentage of CPU usage was recorded during the 10 page loads.
Page load time – Average time taken for the page to load 10 times. Firefox doesn’t have a separate load event time in its Network tab like Chrome does, so we used an addon called app.telemetry Page Speed Monitor to get the times.
The frustrating thing about Firefox is you cannot get accurate scores for memory or CPU usage of extensions during use because unlike Chrome, everything is loaded into a single process. The about:memory page and a few related add ons don’t give a true live score for memory usage. As a result we could only record results for page load times in Firefox.
Tests were conducted on a 4GB, Core Duo 2.2Ghz laptop using WiFi and running Windows 7 as the operating system. Although the tests could have been run on a more powerful system, we believe the laptop will produce more representative scores for the average computer.
All ad blockers were installed and used with their default settings, nothing else was changed. The only exception is Ghostery which runs a wizard on startup where you need to choose what to block, for that we selected only the Advertising blocking option. Chrome 44 and Firefox 40 were the browsers used for testing.
Next we’ll test 10 websites to see how the ad blockers perform.