Douglas Crawford

Douglas Crawford

March 19, 2015

AdBlock Plus (ABP) has for some time now been the go-to browser extension for those who wish to surf the internet unmolested by ads. Even worse than ads, many websites track their visitors as they move on and surf the internet (often using scarily sneaky methods), using the information gleaned to deliver highly targeted advertising, or else selling it on to third party analytics and advertising domains (who use it to deliver highly targeted advertising).

While AdBlock Plus does prevent some of this tracking, browser extensions such as Disconnect, Ghostery, and Privacy Badger do a much better job, and so should usually be used in addition to ABP.

Adblock Plus has come under increasing criticism for:

  1. Whitelisting ads which meet its ‘acceptable ads’ criteria – small companies are listed for free, while larger ones can pay a considerable amount to be whitelisted. While this can be seen a responsible way to handle the fact that many companies rely on advertising to make money, and of enforcing more responsible advertising standards on companies, many users find ads a nuisance that slows down web page loading, and which they have no interest in anyway. ‘Acceptable ads’ can be turned off in ABP’s settings, and Firefox users have the option of using the Adblock Edge fork which has these turned off automatically, but this ‘feature’ has nevertheless annoyed many users.
  2. Being a memory hog – ABP is known for its high RAM usage, which slows down web browsing. This is mainly because it injects up to 4MB of blank CSS into every page, although it is also know to load some scripts even though it does not display them.

Enter uBlock, a new lightweight open source blocker (we should note here that APB is also open source). Rather than being a simple ad-blocker, uBlock describes itself as a ‘general-purpose blocker,’ and should therefore be able to replace anti-tracking extensions such as Disconnect, Ghostery and Privacy Badger.

The uBlock GitHub page shows off some quite impressive test results on how much more memory efficient it is compared to ABP.


When you consider that there is also no need to run an additional anti-tacking extension, the performance benefits are obvious, and in use we felt our Firefox browser to be considerably more sprightly.

uBlock can use the same blocking lists as ABP, and in addition to the default EasyList used by ABP, enables Peter Lowe’s Adservers, EasyPrivacy and Malware domains by default during installation.

As for its effectiveness at preventing tracking, uBlock does not succeed at blocking everything, but it fairs well when compared Disconnect (exact results varied, but in general uBlock seemed to block more elements than Disconnect).

uBlock 2

At, for example, uBlock only succeeded in blocking 21% percent of requests…

uBlock Disconnect

…but this is a considerable improvement over Disconnect. In fact, we rather like the fact that uBlock tells us how often it fails rather than give us a false sense of security

The uBlock web page also contains a number of tests which allow you to compare uBlock with other blockers, and it performed well in our tests, although we were interested to note that it did fail a couple of them.

Individual web pages can be easily whitelisted using the big ‘off’ button, whitelists added or removed etc., and an eye-dropper icon allows you to select page elements to filter interactively.

All-in-all we like uBlocker, it not only runs much faster than ABP, but it negates the need for an additional anti-tracking extension (making your browser run even faster), while providing at least as much anti-tracking protection as other big names in the field.

uBlock is available for Chrome (including Chromium and Opera), Firefox and Safari.