Vivaldi says no to Google's FLoC as well

Martin Brinkmann
Apr 14, 2021
Internet, Vivaldi

More and more Chromium-based browser makers confirm that they won't include Google's FLoC technology in their browsers. DuckDuckGo added FLoC blocking capabilities to its extension recently.  Brave revealed earlier this week that it won't include FLoC in the browser. Vivaldi Technologies published a new blog post on the official company blog in which it confirmed that the Vivaldi browser won't support Google's FLoC either.

FLoC, which stands for Federated Learning of Cohorts, is one of Google's attempts to switch the advertising system from a user-based tracking system to a group-based tracking system. Google, which earns most of its revenue from advertising, paints FLoC in a privacy light because much of its revenue depends on it. A good article on why FLoC is bad is found on the EFF website.

Here is a short summary: FLoC puts Internet users into groups based on interests, instead of relying on cookies and other tracking options. While that sounds good at first, it has several serious disadvantages for the user. With FLoC enabled, any website that you visit may know about the interest group that a user is in; this includes the interests of the group that are generated from the browsing history which it needs to analyze.

Problem is: this happens even on your first visit to the site, so that advertisers and sites know about your interests in gaming, puppies, a football club, or knitting. Even worse, since any FLoC is made up of thousands of users only, it provides fingerprinting techniques with additional information. While FLoC data is changing over time, it is opening an entirely new can of worms.

Any browser that uses Chromium as its source will support FLoC unless it is disabled or removed from it by the browser maker. Vivaldi, which is based on Chromium, is no exception to that, but Vivaldi has a clear message in this regard:

The FLoC experiment does not work in Vivaldi. It relies on some hidden settings that are not enabled in Vivaldi.

We will not support the FLoC API and plan to disable it, no matter how it is implemented. It does not protect privacy and it certainly is not beneficial to users, to unwittingly give away their privacy for the financial gain of Google.

In short: Vivaldi does not support FLoC right now, and it will disable FLoC if it is enabled in Chromium. Other tracking and profiling techniques, even those in disguise, will never find their way either into the browser according to Vivaldi CEO Jon von Tetzchner.

Closing Words

Vivaldi and Brave won't include FLoC in their browsers; it seems unlikely that FLoC will play a huge role outside of Google Chrome.

Article Name
Vivaldi says no to Google's FLoC as well
The Vivaldi web browser won't support Google FLoC, a new advertising technology, because it is not in the interests of users.
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  1. Karl (still a Firefox user) said on April 17, 2021 at 9:49 pm

    April 14
    “What the FLoC? Browser makers queue up to decry Google’s latest ad-targeting initiative as invasive tracking”

    April 17
    “Google’s FLoC flies into headwinds as internet ad industry braces for instability”

  2. Anonymous said on April 16, 2021 at 6:11 am

    Maybe Vivaldi should say no to Google Safebrowsing too, and unique IDs, and spurious connections to amazon etc, and newtab bs. Meet the new guy … same as the old guy, just like the rest of the gang making noise.

    1. Honorius said on April 16, 2021 at 10:14 am

      > Maybe Vivaldi should say no to Google Safebrowsing too
      It’s not a security problem: they use it the same way Firefox does – by downloading the hash database and comparing it locally. The address is not transmitted to Google’s servers.
      But if it’s so critical to you, you could just go into the settings and disable it with one checkbox.

      > and unique IDs
      Suggest a better mechanism. Let’s see how smart you really are. (Besides, they don’t sell or pass it on to anyone)

      > and spurious connections to amazon
      Their servers are hosted by Amazonб isn’t it? How else could it be?

      > and newtab bs
      Didn’t have the cognitive ability to figure out how to delete?

      1. Anonymous said on April 18, 2021 at 12:48 pm

        You popped up only to defend and make excuses for Google checking, ids and unwanted connections, well done. The palpable seething tone betrays the sellout. Their reasons for doing it dont matter – fingers in my ears. Not having this stuff normalized and everywhere would be nice thanks, nothing less.

        Im testing those, cheers. Main brands I relegate to vm now to stop them potentially lifting serials or persisting IDs. Brave im currently getting accustomed to in vm since its quick to get going from install, only a few niggles needing to look into auto fixing.

      2. Iron Heart said on April 18, 2021 at 5:45 pm


        As far as Brave is concerned, here is how I’ve set up mine:

        Hope this helps.

    2. Iron Heart said on April 16, 2021 at 8:40 am


      These browsers have none of the issues you criticize, although in case of SafeBrowsing you could just disable it in Vivaldi’s settings really…

  3. Clemens Ratte-Polle said on April 14, 2021 at 9:47 pm
    1. Peterc said on April 15, 2021 at 11:22 pm

      @Clemens Ratte-Polle:

      In the grander scheme of Internet things, *most* of us are getting “floced” to at least *some* degree… I *was* going to write “we are all *so* floced,” but I know someone, somewhere uses nothing but Tor Browser on Tails from the back seat of a car, while wearing a Guy Fawkes mask, hiding under a blanket, and freeloading on someone else’s secured WiFi that he’s hacked into. ;-)

  4. Yuliya said on April 14, 2021 at 4:49 pm

    I doubt we’ll see this crap in Ungoogled-Chromium either.

  5. Jax said on April 14, 2021 at 4:48 pm

    As an Edge user, I hope Microsoft tells them to stuff it.

    1. Emil Brausewetter said on April 15, 2021 at 5:50 pm

      >>> I hope Microsoft tells them to stuff it.

      Microsofts PARAKEET proposal

      “At Microsoft, we are committed to fostering a healthy web ecosystem where everyone can thrive – consumers, publishers, advertisers, and platforms alike. Protecting user privacy is foundational to that commitment and is built into Microsoft Edge with features like Tracking Prevention, Microsoft Defender SmartScreen, and InPrivate browsing. We also support an ad-funded web because we don’t want to see a day where all quality content has moved behind paywalls, accessible to only those with the financial means.”

      How noble:

      “We also support an ad-funded web because … rhabarba … rhabarbarum …”

      Still any question?


  6. Daniel said on April 14, 2021 at 2:50 pm

    +1 to JohnnyP for making Vivaldi default.

    Ex-diehard long time Firefox fan here too!

    Btw, uBlockOrigin will block FLoC in its next release (maybe done by now too).

    1. Beta said on April 15, 2021 at 2:21 pm

      I agree, Dan. I have been using Firefox for many years. I also use the addons AdBlock Plus and Privacy Badger. I used this website to check Firefox:
      It shows “Your browser does not have FloC enabled.”
      I do almost everything I can to stay private. But if you block everything, you can’t do anything.
      I have been using “Startpage” as my search engine for several years.

      1. Iron Heart said on April 15, 2021 at 2:44 pm


        > I also use the addons AdBlock Plus and Privacy Badger.

        uBlock Origin is superior to, and replaces, both of these.

  7. anona said on April 14, 2021 at 10:30 am

    I wonder what Edge and Opera will do? These are the biggest Chromium-based non-Chrome browsers by market share.

  8. Pedro said on April 14, 2021 at 10:19 am

    If Microsoft says no to FLoC, Google is screwed. I really hope they do that.
    This is interesting to watch as a Firefox user though.

    1. Anonymous said on April 14, 2021 at 12:33 pm

      Well as a Firefox user I’m worried because Google decides everything in Firefox infact Google will strip all add-ons from Firefox in few months. And also Fox has died as Firefox Browser is Chrome in disguise and all its features have gone. Firefox even has FLoc which we can’t even see and Google has basically shipped all Firefox users in alternate reality where they think that Google is only a search engine partner which can be easily changed in few seconds and Mozilla only applies security things from Google and respects user privacy.

      1. Nico said on April 15, 2021 at 11:35 am

        FLoC is a Chrome/Chromium “feature” only. Firefox doesn’t have it, nor will it be implemented.
        You can dig through the source code and you will not find it. :)

        >infact Google will strip all add-ons from Firefox in few months.

        That’s new to me.
        Could you provide a link?

      2. Anonymous said on April 15, 2021 at 6:33 pm

        Tbf profiling is not suddenly a Chrome/Chromium “feature” only, profiling has been a thing in Firefox for years with their own special implementations. Theyre part of the gang normalizing this sort of stuff. We mustn’t stop resisting any of it just because google does it too, its expected of google.

      3. Anonymous said on April 15, 2021 at 4:43 pm

        @Nico, It was a joke, nothing else, that’s why I praised Firefox in last lines after writing starting ones for fun.

      4. Iron Heart said on April 15, 2021 at 2:43 pm


        Firefox not having FLoC is no different from a Chromium having FLoC disabled. It’s not active in either case.

        Firefox has other privacy issues, though.

      5. Emil Brausewetter said on April 15, 2021 at 9:53 pm

        Between “not having FLoC” and “having FLoC disabled” is a very BIG difference:

        FLoC is a “moving target” in it’s first wide-scale test and not disabled forever by the first shot!

        The next crap is already waiting in the wings, via a proposal called FLEDGE from Chrome, which was recently added to the Privacy Sandbox.

        FLEDGE is the early prototype for ad serving based on Chrome’s TURTLEDOVE framework and includes a number of different components from other sandbox proposals: eg. Criteo’s SPARROW, DOVEKEY from the Google Ads team, Magnite’s PARRROT and Nextroll’s TERN … and so on …

        Have fun deactivating! →

        Tu felix Firefox, bella gerant alii.

      6. Iron Heart said on April 16, 2021 at 8:38 am

        @Emil Brausewetter

        > FLoC is a “moving target”

        And? Does that mean that internal kill switches (which are also necessary for Google, because otherwise they’d have no way to quickly disable features in case of breaking bugs or security issues) will suddenly stop working?

        The setting for disabling WebRTC in Firefox also still works (and retains its name and location) despite WebRTC receiving patches all the time. Same story here.

        Felix Firefox?

        Deplatformingfox is supportive of shit like this:

        This is DISGUSTING and blatantly ANTI-USER. Mozilla ultimately serves their Google paymasters and no one else.

      7. Emil Brausewetter said on April 16, 2021 at 10:32 am

        > FLoC is a “moving target”

        >>> And?

        And … there will likely be a lot of changes to this code in the upcoming releases.

        Keep on patching ’till the “internal switches” kill you … remember that “Moorhuhn Shooter”?

        Shoot a chicken and five new ones will appear …🐔🐔🐔🐔🐔

      8. Iron Heart said on April 16, 2021 at 1:17 pm

        @Emil Brausewetter

        Care to come up with a reply that is not asinine for once? Asking for a friend.

  9. JohnnyP said on April 14, 2021 at 9:39 am

    Oh man, I left firefox years ago after the armagadd-on fuckup, to vivaldi and never looked back.
    I have been since then very happy with vivaldi.
    Last version even made a significant UI speed boost.

    For me, vivaldi is now what firefox was a decade or more ago.
    Updates with user needs in mind.

  10. Anonymous said on April 14, 2021 at 9:32 am


    Official info over here:

    1. Anonymous said on April 14, 2021 at 6:29 pm

      Vivaldi stores the approximate location of the user (derived from the IP address minus the last octet) every 24 hours, tied to this unique ID.

  11. Anonymous said on April 14, 2021 at 9:10 am

    F#%$ FLoC

  12. Cor said on April 14, 2021 at 9:09 am

    Would be interesting if Google and Microsoft forked and abandoned Chromium.

  13. Lemegeton said on April 14, 2021 at 9:05 am
  14. Klaas Vaak said on April 14, 2021 at 8:57 am

    @Martin Brinkmann: Vivaldi used to use a unique user ID to track the use of its browser, but it stopped doing that 1 or 2 years ago. As far as you know, do they do anything else that is comparable to identifying users?

  15. Anonymous said on April 14, 2021 at 8:31 am

    What are the features in Vivaldi that are not in other browsers? Asking for a friend(Vivaldi users don’t take it personally)

    1. Martin Brinkmann said on April 14, 2021 at 8:32 am

      Check out our Vivaldi review for an overview:

      1. Anonymous said on April 14, 2021 at 12:22 pm

        Thank you, Martin

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