Why Apple and Google Are Killing Third Party Cookies

Third-party cookies are the cockroaches of the internet—everyone hates them, but they refuse to die. That is, until two of the biggest tech companies on the planet decided they'd had enough.

Apple and Google are both dismantling third-party cookies in their browsers. Safari has blocked them by default since 2020. Google is rolling out its "Privacy Sandbox" to replace cookies in Chrome by late 2024. But the reasons go deeper than just “privacy”.

The Swiss Army Knife of tracking

A third-party cookie is a tiny text file set by a website other than the one you're visiting. If you visit a news site and see an ad from a company called AcmeAds, AcmeAds can drop a cookie on your browser. Then, when you visit another site that also uses AcmeAds, that cookie tells them: “Oh, it's you again!”

Over time, that builds a profile of everything you do across the web—sites you browse, products you buy, articles you read, even pages you just glance at. That profile is worth serious money.

But it also has a serious creep factor.

Apple’s real reason: competitive moat

Apple’s public stance is about user privacy. They run campaigns like “Privacy. That’s iPhone.” But there's a less noble reason under the hood.

Apple makes its money selling hardware and services like iCloud and Apple Music. It does not rely on advertising revenue. Third-party cookies, by contrast, fuel the advertising empires of Google and Facebook. By killing cookies, Apple hurts its biggest competitors without affecting its own business model.

In fact, Apple’s own ad network—which runs ads in the App Store and Apple News—can still use first-party data. So Apple blocks what other companies do, while continuing to do its own version of targeted advertising.

Google’s dilemma: shooting its own foot

Google has a much harder problem. Chrome is the world’s most popular browser, with about 65% market share. And most of Google’s revenue—over $200 billion a year—comes from advertising, much of it powered by cookies.

Killing cookies seems suicidal. But here's the thing: regulators in Europe, the UK, and the US are circling. If Google doesn’t act, they will be forced to. The GDPR and ePrivacy Directive already restrict cookie use. Google sees cookie-killing as a way to shape the replacement—on its own terms.

That’s the Privacy Sandbox: a set of APIs that let advertisers still show relevant ads, but without individual tracking. For example, the FLoC (Federated Learning of Cohorts) approach groups people into large anonymized “cohorts” based on browsing habits. Advertisers target the cohort, not the individual.

What replaces third-party cookies?

Both Apple and Google have alternatives, and they are fundamentally different:

• Apple’s SKAdNetwork – Used for app installs. It hides conversion data and delays reporting to prevent linking individual users.
• Google’s Topics API – Instead of tracking you, Chrome tells advertisers you've shown interest in “Fitness” or “Automotive” this week, based on your recent browsing. No individual data leaves your device.
• First-party data – Companies like Amazon and Walmart already have massive amounts of data from their own platforms. They don’t need third-party cookies.
• Contextual advertising – Showing a sports ad on a sports article works just as well as targeting someone who searched for sneakers last week.

The hidden winner: big tech itself

Here’s the uncomfortable truth: killing third-party cookies doesn't kill advertising. It just shifts power from a scattered ecosystem of adtech middlemen toward the biggest platforms that own the browsers, the operating systems, and the user data.

Apple already knows who you are. Google already knows who you are. They don’t need cookies to track you—they have your login, your email, your device ID. The companies that lose are the smaller ad networks that relied entirely on third-party cookies. The companies that win are Apple and Google.

What it means for users

For the average person, the death of third-party cookies means:

• Less creepy ads – You won't see an ad for shoes you looked at three days ago while reading a news article.
• More login-wall tracking – Sites will ask you to create an account so they can track you using first-party cookies instead.
• Less targeted, less relevant ads – Some will see this as a win (privacy), others as a loss (you'll see more random ads for stuff you don't want).

The bottom line

Third-party cookies are dying not because tech companies suddenly grew a conscience, but because the business dynamics have shifted. Apple wants to hurt its rivals. Google wants to control its own regulatory fate. Both want to consolidate their power over the ad market.

Users get a side effect of better privacy—but it comes with a catch: the new systems are still designed to serve ads, just more opaque ones. The cockroaches aren't gone. They're just evolving into something harder to spot.