AdGuard Blog: Microsoft Edge is getting rid of third-party cookies. What about their replacement?

[Gandalf_The_Grey]

Following in the footsteps of Google Chrome, Microsoft Edge has announced that it would be phasing out third-party cookies. In the upcoming months, Microsoft said it plans to begin trials with discontinuing Edge’s use of third-party cookies, starting with 1% of users. These cookies, once the linchpin of targeted advertising, have been instrumental in crafting intricate user profiles.

Historically, third-party cookies — tiny data files placed on your browser by sites other than the one you’re visiting — have enabled advertisers to track your visits across all the platforms where they advertise. That’s why the role of the “tracking” cookie in spawning a surveillance economy where user data is treated as a commodity they have no control over can hardly be overestimated.

But as users have become more privacy-conscious, and regulators — primarily in the EU and California — began scrutinizing the handling of personal data, the third-party cookie has been on a steady retreat. Google Chrome’s move earlier this year to finally, after multiple delays, embark on phasing out third-party cookies was a significant blow, effectively sounding the death knell for this tracking technology. Given Chrome’s dominance in the browser market, it’s unsurprising that Microsoft Edge has followed suit. Meanwhile, browsers like Apple Safari and Mozilla Firefox, along with privacy-centric browsers such as Brave, have already been proactively blocking third-party cookies by default.

...

Final thoughts

Microsoft’s plan to phase out third-party cookies in favor of a novel ad targeting mechanism is quite ambitious. But there are just too many pieces of the puzzle that need to fall into place for it to work smoothly. Finding an adequate replacement for a system that has been entrenched for years is undeniably a formidable challenge, but is it insurmountable? Time will tell.

On the other hand, browsers like Safari and Firefox have long since gotten rid of third-party cookies without causing the ad tech companies to go under. Which begs an important question: How vital were these third-party cookies for the ad tech businesses, and is it truly necessary to find a replacement, or could they simply be discarded?

The answers to these questions will largely depend on Microsoft’s implementation of the new API. However, the fact that its Ad Selection API resembles Protected Audience API to such an extent raises concerns about the potential implications for user privacy.

Since we believe that Protected Audience API is not as private as Google claims it to be, AdGuard has already blocked this API for users who have AdGuard’s Tracking Protection filter enabled. In the meantime, we are working on more advanced ways to disable it. As for Microsoft’s Ad Selection API, which we believe bears uncanny resemblance to Google’s API, our approach will be the same — as soon as Microsoft implements it in Edge, we will start blocking it as well.

Edge replaces 3d party cookies with a new API. How private is it?

Microsoft Edge is getting rid of third-party cookies — the linchpin of cross-site tracking. But their replacement poses privacy risks as well.

adguard.com

 

[SpiderWeb]

This is hilarious considering Microsoft has 80+ domains and it is pretty much the only reason I still need to have the setting enabled at work or else Microsoft Teams doesn't load when you get redirected from Outlook through URL Defense through Microsoft Office until you finally arrive at Teams. This will get a lot of push back from companies that rely on Microsoft because of legacy systems.

 

[oldschool]

Since we believe that Protected Audience API is not as private as Google claims it to be, AdGuard has already blocked this API for users who have AdGuard’s Tracking Protection filter enabled. In the meantime, we are working on more advanced ways to disable it. As for Microsoft’s Ad Selection API, which we believe bears uncanny resemblance to Google’s API, our approach will be the same — as soon as Microsoft implements it in Edge, we will start blocking it as well.

Just another reason to switch to Adguard in most chromium browsers.

 

[oldschool]

Here's what MS will do.

New Privacy-Preserving Ads API coming to Microsoft Edge

In recent years, the web browser ecosystem has begun to pursue a path toward evolving the web platform in ways that reduce pervasive cross-site tracking of users. With built-in

blogs.windows.com

And this link from the above link explains more detail and how different browsers have approached 3rd party cookies.

GitHub - privacycg/CHIPS: A proposal for a cookie attribute to partition cross-site cookies by top-level site

A proposal for a cookie attribute to partition cross-site cookies by top-level site - privacycg/CHIPS

github.com

 

[nicolaasjan]

Not So Protected Audience Demo

In the meantime in Firefox:

For the 0.1% of the time that I use a Chromium browser, I hope there will always be ways to opt-out of this nonsense.
For now, I believe this is the way to do that in chrome://settings/adPrivacy :
(Chromium 125)

 

[TairikuOkami]

I really do hope they will take care of it soon, the notice is annoying and 5 times a day it takes half of the screen, I will post a screenshot, when I get it. I do not even bother closing the little one.

 

[Morro]

Just another reason to switch to Adguard in most chromium browsers.

Just a curious question, does that mean you would advise people to already switch from uBlock Origin to Adguard MV3 Experimental in Brave and Opera One?

 

[Azazel]

Just a curious question, does that mean you would advise people to already switch from uBlock Origin to Adguard MV3 Experimental in Brave and Opera One?

For Brave it won't be needed, for everything else yes. By June Adguard MV3 Experimental will be stable and all Manifest V2 extensions won't be available.

 

[Morro]

For Brave it won't be needed, for everything else yes. By June Adguard MV3 Experimental will be stable and all Manifest V2 extensions won't be available.

I could indeed switch to Braves own later on. Guess I will have a look at AdGuard MV3 for Opera One some more then.

 

[Virtuoso]

I could indeed switch to Braves own later on. Guess I will have a look at AdGuard MV3 for Opera One some more then.

Adguard has announced that they will seamlessly update their normal Adguard extension to MV3 version in Chrome webstore, the current MV3 Experimental version is for testing and review purpose. So, you can use the normal Adguard extension and it will automatically be MV3 compatible when the time comes.

 

[nicolaasjan]

By June Adguard MV3 Experimental will be stable and all Manifest V2 extensions won't be available.

(Offtopic)
You can extend MV2 extension availability by 1 year with an enterprise policy in Chromium browsers.

This way you can enjoy the full functionality of MV2 uBlock Origin in Chromium for another year.
(I guess you'll have to download it from GitHub then, since it won't be available in the Webstore any more )

After that we'll see.

Manifest V2 support timeline | Extensions | Chrome for Developers

June 2025: Chrome MV2 deprecation enterprise rollout​

Enterprises using the ExtensionManifestV2Availability policy to ensure the continued functioning of Manifest V2 extensions in their organization will have one additional year - until June 2025 - to migrate the Manifest V2 extensions in their organization. Browsers with the policy enabled will not be impacted by the rollout of the deprecation until that time.

For Chrome browser, apply this .reg file:

Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome] "ExtensionManifestV2Availability"=dword:00000002

For Edge:
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Edge] "ExtensionManifestV2Availability"=dword:00000002


BTW, for those not using the Adguard extension, in uBO this "privacy" API will be blocked by the built-in AdGuard Tracking Protection list.

 

[Morro]

Well, it is good to see that AdGuard allowed me to import “My Rules” from uBlock Origin, otherwise I would have been busy getting them into AdGuard manually. I will keep uBlock Origin installed for a week or two, (But deactivated) to see how AdGuard is these days. I am so used to uBlock Origin, but I will have to give AG a good chance, due to the coming changes.

 

[nicolaasjan]

Well, it is good to see that AdGuard allowed me to import “My Rules” from uBlock Origin, otherwise I would have been busy getting them into AdGuard manually. I will keep uBlock Origin installed for a week or two, (But deactivated) to see how AdGuard is these days. I am so used to uBlock Origin, but I will have to give AG a good chance, due to the coming changes.

Here is a Reddit thread that states there will not be an automatic update from uBO to uBO Lite.

There are chromium engine browsers that will not be removing mv2, so uBO will not drop chromium support anyway.

Do you think that the coming changes can't be tackled by uBO?

 

[oldschool]

Just a curious question, does that mean you would advise people to already switch from uBlock Origin to Adguard MV3 Experimental in Brave and Opera One?

I would never advise µBO in Brave unless you exclusively use medium or hard mode. I've never used Opera so I've no idea.

 

[Morro]

I would never advise µBO in Brave unless you exclusively use medium or hard mode. I've never used Opera so I've no idea.

Thank you, and I am still using uBlock Origin in medium mode in Brave, but tomorrow I will take another look at Brave's own Shields.