Chrome to Block Third-Party Cookies

John Lister's picture

Google says it will block third-party cookies, which can track Internet users in ways they don't expect. But it could be up to two years before the block is fully in place.

A cookie is a small text file placed on a user's computer by a website. The idea is the site can check for the cookie later on and customize the users' web experience. Examples of 'legitimate' cookie use would be an online store that holds items in a virtual 'shopping basket', and a movie theater chain's site 'remembering' a user's location to automatically show them local listings.

The more controversial variant is third-party cookies that operate when the user is visiting a site other than the one which issued the cookie.

The most notorious use is to track a user's activity online, commonly for advertising purposes. For example, an online retailer might use third-party cookies to discover a user's interests from the sites they browser, then display targeted ads either as popups or when they visit the retailer's site.

Chrome Lags Behind Rivals

Safari and Firefox already block third-party cookies by default. Google has been more hesitant with the Chrome browser, with many thinking it fears such a move would reduce the effectiveness and popularity of online advertising, one of its major areas of business.

Google has argued that simply cutting off third-party cookies would drive less reputable companies to use more sinister techniques such as fingerprinting.

This approach combines dozens of pieces of information revealed by a browser (from screen resolution to installed font typefaces) to try to identify individuals. (Source:

New Approach To Privacy

Google has now said it will slowly phase out support in Chrome for third-party cookies, possibly not removing it completely for a couple of years.

The first step towards this will come next month when it will start only allowing third-party cookies if they are clearly labeled as such and only use secure web connections.

Google says the two-year delay will let it develop a new "privacy sandbox" approach that minimizes the amount of data advertisers need to show relevant ads. It says it wants to make this approach a web standard which will involve time-consuming testing and negotiation. (Source:

What's Your Opinion?

Do you buy Google's argument that it can't simply block third-party cookies outright now? Is it a conflict of interests that the most popular browser is developed by a major player in online advertising? Should browser developers set defaults for cookie practices or leave it to users to control?

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stekcapofni's picture

Google is taking time to make sure that when they block third party cookies that Google can still access any of your cookies they want to.

russoule's picture

many, if not most, of the sites I go to have a notification that it "uses cookies to blah,blah,blah" and some sites won't allow access unless cookies are enabled. Google will have a real problem trying to convince all these sites to change their design just so Chrome will work on them. I can understand why they claim it will be a long process.