uBlock Origin's Logger highlights the extension's activity

Martin Brinkmann
Jul 1, 2015

Have you ever asked yourself what ad-blocking scripts and extensions like uBlock Origin do after they have been installed?

While it is clear that they block or allow network requests or DOM elements, it is usually not that simple to find out about all activity in detail.

The excellent Chrome and Firefox extension uBlock Origin comes with a Logger that has been designed specifically for that as it reveals all of the extension's activity.

This gives interested users an option to control what the extension is doing when enabled in the browser they are using.

There are several applications for this: check what is being blocked to make sure that no critical page elements are included, control that custom rules are working properly, or diagnose why some elements are not covered by existing rules.

A click on the uBlock Origin button in the interface of the browser that you are using opens a small menu that allows you to control the state of the extension as well as specific features. The Logger icon is displayed next to the "element picker" icon in the middle of the interface.

ublock origin logger

Note: The logger only logs activity if it is open. This is done to keep the extension efficient and avoid cpu and memory usage.

A new page is opened afterwards that displays all activity in chronological order. Each entry is listed with a timestamp, its type (e.g. popup, script or dom), the page the manipulation was carried out on, DOM elements if the type is DOM, and rules that blocked scripts from being loaded.

If you are interested in a particular web page you may use the filter at the top to display only its activity. There you find listed all open tabs in the browser sorted alphabetically. Instead of doing that, you may also use the search filter to find specific activities, for instance specific rules.

ublock origin log

A click on a log entry displays information about the filter and the list it is found in. While you can simply type and get results, you may use filter expressions to customize the output. For instance, to find entries that match what you type exactly, use |example| and replace example with the search term.

Another interesting feature provided by the Logger is quick access to uBlock's advanced filtering options. You do need to enable the "advanced user" option in the program options first though before this becomes available.

A click on the second column in the logger opens the interface for the listed page/domain.

ublock origin advanced

Another useful feature is called "Behind the scene". You find it listed in the page selection menu, and it lists requests that uBlock cannot associate with a domain.

This includes among other things requests made by the browser itself, made by extensions, and by websites if technologies such as hyperlink auditing are used.

You may create dynamic URL filtering rules or static network filters from the Logger interface. These let you create temporary or permanent filters, and are useful in finding out which network requests need to be blocked or allowed on a page.

Closing Words

The log capabilities of uBlock Origin are quite powerful. While it may not be of interest to the majority of users who use the extension in Firefox or Chrome, it provides advanced users with options to monitor, control and fine-tune the browser extension.

uBlock Origin's Logger highlights the extension's activity
Article Name
uBlock Origin's Logger highlights the extension's activity
A detailed look at the Logger component of the uBlock Origin extension for Firefox and Chrome which highlights the extension's activity.

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  1. ilev said on August 4, 2012 at 7:53 pm

    Doesn’t Windows 8 know that www. or http:// are passe ?

    1. Martin Brinkmann said on August 4, 2012 at 7:57 pm

      Well it is a bit difficulty to distinguish between name.com domains and files for instance.

    2. Leonidas Burton said on September 4, 2023 at 4:51 am

      I know a service made by google that is similar to Google bookmarks.

  2. VioletMoon said on August 16, 2023 at 5:26 pm

    @Ashwin–Thankful you delighted my comment; who knows how many “gamers” would have disagreed!

  3. Karl said on August 17, 2023 at 10:36 pm


    The comments section under this very article (3 comments) is identical to the comments section found under the following article:

    Not sure what the issue is, but have seen this issue under some other articles recently but did not report it back then.

  4. Anonymous said on August 25, 2023 at 11:44 am

    Omg a badge!!!
    Some tangible reward lmao.

    It sucks that redditors are going to love the fuck out of it too.

  5. Scroogled said on August 25, 2023 at 10:57 pm

    With the cloud, there is no such thing as unlimited storage or privacy. Stop relying on these tech scums. Purchase your own hardware and develop your own solutions.

    1. lollmaoeven said on August 27, 2023 at 6:24 am

      This is a certified reddit cringe moment. Hilarious how the article’s author tries to dress it up like it’s anything more than a png for doing the reddit corporation’s moderation work for free (or for bribes from companies and political groups)

  6. El Duderino said on August 25, 2023 at 11:14 pm

    Almost al unlmited services have a real limit.

    And this comment is written on the dropbox article from August 25, 2023.

  7. John G. said on August 26, 2023 at 1:29 am

    First comment > @ilev said on August 4, 2012 at 7:53 pm

    For the God’s sake, fix the comments soon please! :[

  8. Kalmly said on August 26, 2023 at 4:42 pm

    Yes. Please. Fix the comments.

  9. Kim Schmidt said on September 3, 2023 at 3:42 pm

    With Google Chrome, it’s only been 1,500 for some time now.

    Anyone who wants to force me in such a way into buying something that I can get elsewhere for free will certainly never see a single dime from my side. I don’t even know how stupid their marketing department is to impose these limits on users instead of offering a valuable product to the paying faction. But they don’t. Even if you pay, you get something that is also available for free elsewhere.

    The algorithm has also become less and less savvy in terms of e.g. English/German translations. It used to be that the bot could sort of sense what you were trying to say and put it into different colloquialisms, which was even fun because it was like, “I know what you’re trying to say here, how about…” Now it’s in parts too stupid to translate the simplest sentences correctly, and the suggestions it makes are at times as moronic as those made by Google Translations.

    If this is a deep-learning AI that learns from users’ translations and the phrases they choose most often – which, by the way, is a valuable, moneys worthwhile contribution of every free user to this project: They invest their time and texts, thereby providing the necessary data for the AI to do the thing as nicely as they brag about it in the first place – alas, the more unprofessional users discovered the translator, the worse the language of this deep-learning bot has become, the greater the aggregate of linguistically illiterate users has become, and the worse the language of this deep-learning bot has become, as it now learns the drivel of every Tom, Dick and Harry out there, which is why I now get their Mickey Mouse language as suggestions: the inane language of people who can barely spell the alphabet, it seems.

    And as a thank you for our time and effort in helping them and their AI learn, they’ve lowered the limit from what was once 5,000 to now 1,500…? A big “fuck off” from here for that! Not a brass farthing from me for this attitude and behaviour, not in a hundred years.

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