Blog - What Are Tracking Cookies? A Simple Explanation for Website Owners

If you run a website, you’ve heard about tracking cookies. Maybe you’ve nodded along in meetings when someone mentioned them. Maybe you’ve just ignored the whole thing and hoped your marketing team had it covered.

Here’s what you actually need to know: tracking cookies are how websites remember people. They’re how you know someone came back, what they looked at, whether they bought anything.

For two decades, they’ve been the invisible infrastructure that makes online marketing work.

And now? They’re breaking down.

Safari limits cookies to seven days. Privacy browsers block them entirely. GDPR makes you ask permission before using them. Apple’s privacy rules mean you’re probably only seeing half of what’s really happening on your site.

That’s not coming. That’s already here.

Let’s talk about what tracking cookies actually are, how they work, and what’s replacing them — in plain terms, no jargon, no marketing speak.

A tracking cookie is a small text file that gets stored on someone’s device when they visit your website.

Think of it like this: You run a coffee shop. A regular customer walks in. You remember them because last time they ordered a cappuccino, sat by the window, and read the newspaper for an hour. When they come back, you recognize them. Maybe you remember their usual order. Maybe you notice they always come in on Tuesdays.

That’s what a tracking cookie does for your website.

When someone visits your site, your server drops a tiny file on their browser. Next time they show up — even weeks later — your site recognizes them. You can see they came back three times before buying. You know they started on mobile and finished on desktop. You remember they abandoned a shopping cart.

What makes tracking cookies different from regular cookies?

They stick around. Session cookies disappear the moment someone closes their browser. Tracking cookies can last for days, months, even years. This persistence is what lets you track behavior over time.

They connect the dots. Someone clicks your Facebook ad today, visits your site, leaves, comes back from a Google search next week, and makes a purchase. A tracking cookie ties all of that together. Without it, you’d assume Google deserved all the credit.

They enable memory. Ever notice how some websites remember your preferences, show you products you looked at before, or don’t make you log in every single time? Tracking cookies.

It’s simple when it works. The problem is, it’s not working anymore.

How Tracking Cookies Actually Work

When someone lands on your website, here’s what happens:

Your site sends a small piece of data to their browser. The browser stores it as a cookie. Every time that person visits your site again, their browser sends the cookie back to your server.

It looks like this:

First visit: Someone finds your site through a Google search. Your tracking code (Google Analytics, Meta Pixel, whatever you’re using) generates a unique ID for this visitor. This ID gets stored in a cookie on their device.

Activity tracking: They browse around. Look at products. Read a blog post. Fill out half of a contact form and bail. The cookie records all of this and associates it with their unique ID.

Return visit: Two weeks later, they come back. Their browser sends the cookie to your server. Your site recognizes the ID and can see their entire history. “This person visited three times, looked at five products, started checkout but didn’t finish.”

Cross-site tracking: Some cookies (third-party cookies) work across different websites. This is how retargeting works. You look at a jacket on one site, and suddenly you’re seeing ads for that jacket on completely different websites for the next two weeks.

Except here’s the thing: browsers are killing this system.

Safari limits cookies to seven days now. If someone takes two weeks to decide whether to buy your product, you’ve lost the connection between their first visit and their eventual purchase. Your analytics will tell you they’re a brand new visitor, even though they’ve been researching you for weeks.

Chrome is phasing out third-party cookies entirely. Firefox and Safari already block them by default.

The infrastructure we’ve relied on for 20 years is being dismantled, piece by piece.

Types of Tracking Cookies

Not all cookies work the same way. Here’s what you’re actually dealing with:

First-Party Cookies

These come from your own domain. When someone visits yoursite.com, the cookie says yoursite.com.

What they do: Remember login status, shopping cart items, user preferences, basic site analytics.

Browser treatment: Generally allowed. Safari still limits them to seven days, but they’re not blocked outright.

What this means for you: You own this data. It lives on your servers. You control it.

Third-Party Cookies

These come from a different domain than the one you’re visiting. If you’re on yoursite.com but the cookie comes from facebook.com or googleadservices.com, it’s a third-party cookie.

What they do: Power ad retargeting, cross-site tracking, audience building for ad platforms.

Browser treatment: Basically dead. Safari and Firefox block them by default. Chrome is phasing them out.

What this means for you: The retargeting and lookalike audiences you’ve relied on for years? Going away.

Session Cookies

These die the moment someone closes their browser.

What they do: Keep you logged in during a single visit. Remember items in a shopping cart before checkout.

Browser treatment: No one’s blocking these. They’re temporary.

What this means for you: Fine for basic site functionality. Useless for tracking long-term behavior.

Persistent Cookies

These stick around for a set period. Could be days, months, years.

What they do: Remember login credentials across sessions, track behavior over multiple visits, enable long-term analytics.

Browser treatment: Increasingly restricted. Safari caps them at seven days. Other browsers are tightening the window.

What this means for you: If your sales cycle is longer than a week, you’re already losing attribution data.

Here’s the uncomfortable truth: most marketing and analytics depend on persistent, third-party cookies. Those are exactly the cookies that modern browsers are killing.

What Website Owners Use Tracking Cookies For

If you run a website, tracking cookies are probably doing more heavy lifting than you realize.

Understanding Your Audience

Cookies tell you who’s visiting, where they came from, what pages they viewed, how long they stayed. Without this, you’re guessing. You don’t know if your blog is working. You don’t know if your ads are driving traffic. You don’t know if anyone actually reads your About page.

Measuring Marketing Performance

Did that Facebook ad campaign work? Did your email newsletter drive traffic? Without tracking cookies, you can’t connect the click on your ad to the visitor who showed up on your site. You’re spending money with no way to tell what’s working.

Retargeting and Personalization

You know how you visit a site, leave, and then see their ad follow you around the internet for two weeks? That’s cookie-based retargeting. For e-commerce, this is often the difference between a 2% conversion rate and a 5% conversion rate. It works because you’re showing ads to people who already showed interest.

Improving User Experience

Cookies remember login info, language preferences, shopping cart contents, form data. Without them, every visit feels like the first visit. Your users start over every single time.

The catch: All of this assumes cookies are lasting long enough to track meaningful behavior. With Safari’s seven-day limit and browsers blocking third-party cookies entirely, that assumption no longer holds.

What Marketers and Advertisers Use Tracking Cookies For

If you’re buying ads or running campaigns, cookies are even more critical.

Attribution and ROI

You need to know which ads, emails, or campaigns drove actual conversions. Tracking cookies connect the click on your ad to the purchase that happened three days later. Without that connection, you can’t calculate ROI. You’re just guessing.

Audience Building

Meta and Google let you build custom audiences based on website behavior. People who viewed specific products, spent time on certain pages, added items to cart but didn’t buy. All of this requires cookies to identify and track those visitors.

A/B Testing

Want to test two different landing pages? Cookies ensure the same visitor sees the same version consistently, so your test results mean something.

The hidden problem: If your cookies only last seven days in Safari — which is 30-40% of all web traffic — you’re missing huge chunks of your customer journey. Someone clicks your ad, browses, leaves, comes back two weeks later and buys. Your analytics won’t connect those dots. You’ll think the campaign failed when it actually worked.

Tracking cookies aren’t just a technical problem anymore. They’re a legal one.

If you have visitors from the EU, GDPR requires explicit consent before you can use non-essential tracking cookies. That’s why you see cookie consent banners everywhere. Ignore this and you’re looking at fines up to 4% of annual revenue.

CCPA (California)

California’s privacy law gives residents the right to know what data you’re collecting and opt out of its sale. Cookies that share data with third parties fall under this.

Other Regulations

More states and countries are passing similar laws. The trend is clear: more restrictions, more consent requirements, more transparency.

What this means for you: Cookie consent banners reduce the percentage of visitors you can track. Even when you’re fully compliant, you’re starting from incomplete data. Studies show 40-60% of visitors decline cookie consent or close the banner without responding.

You’re not just losing data from browser restrictions. You’re losing it from legal restrictions too.

The Future of Tracking: What’s Replacing Cookies?

Third-party cookies are dying. Browser restrictions are tightening. Privacy regulations are expanding.

So what comes next?

First-Party Data and Server-Side Tracking

The biggest shift is toward first-party tracking — data collected directly by your website, stored on your own domain, processed on your own servers.

Instead of relying on third-party cookies set by ad platforms, modern tracking systems use server-side methods that browsers don’t block.

Here’s why this matters: first-party tracking can see the visitors that traditional cookies miss.

Safari limits standard cookies to seven days. But first-party server-side tracking can maintain visitor identity for weeks or months — long enough to capture real buying journeys.

Tools like Waterloo Track use this approach. By setting first-party cookies at the server level, they restore the visibility that traditional tracking has lost. You stop missing 30-50% of your audience. Your attribution becomes accurate again. You can actually see which marketing is working.

It’s not a workaround. It’s a different architecture that works with modern privacy rules instead of fighting them.

Cookieless Tracking Technologies

Some platforms are developing fingerprinting and other cookieless methods to identify visitors. These come with their own privacy concerns and browsers are restricting those too.

Privacy-Focused Analytics

Tools like Plausible and Fathom Analytics don’t use cookies at all. They provide aggregate traffic data without individual tracking. The tradeoff: you lose attribution, personalization, and the ability to measure detailed customer journeys.

The reality: The future belongs to first-party data. If you’re still relying entirely on third-party pixels and standard cookie implementations, you’re already seeing incomplete data. And the gap is widening.

Should You Still Use Tracking Cookies?

Short answer: Yes, but not the way you used to.

Here’s what that actually means:

Keep using first-party cookies for essential functions. Login persistence, shopping carts, user preferences. These aren’t going anywhere. Browsers still support first-party functional cookies.

Accept that third-party cookies are finished. Don’t build marketing strategies that depend on them. Chrome is phasing them out. Safari and Firefox already block them. By 2026, they’ll be effectively dead.

Upgrade to modern tracking methods. First-party server-side tracking gives you the visibility cookies used to provide, without the browser restrictions. This isn’t optional anymore. It’s how you stop flying blind.

Be transparent and compliant. Use cookie consent tools. Write clear privacy policies. Respect opt-outs. The legal risks aren’t worth ignoring.

Measure what you’re missing. If you’re only using standard client-side tracking (Google Analytics, Meta Pixel), you’re probably missing 30-50% of your visitors. Run a comparison test with first-party server-side tracking to see the actual gap.

Real example: One nonprofit we worked with thought their email campaigns weren’t working. Standard tracking showed minimal traffic from email. When we implemented first-party server-side tracking, email accounted for 40% of donations. It was working the whole time. Safari’s seven-day cookie limit was just hiding the conversions.

The data was always there. They just couldn’t see it.

What to Do Next

If you’re running a website and you’re not sure whether your tracking is accurate, here’s where to start:

Check your Safari traffic. Open Google Analytics and filter for Safari users. That’s 30-40% of your audience operating with seven-day cookie limits. If your buying cycle is longer than a week, you’re missing attribution.

Review your cookie consent rates. If only 50% of visitors accept cookies, you’re making marketing decisions based on half the data.

Test first-party tracking. Compare your current analytics to a first-party server-side implementation. The difference is usually eye-opening. Most businesses discover they were missing 30-50% of conversions.

Future-proof your stack. Browsers aren’t reversing course on privacy. Cookie restrictions will keep tightening. Invest in tracking infrastructure that works with modern privacy standards, not against them.

The shift from third-party cookies to first-party tracking isn’t coming. It already happened. The question is whether you’re adapting fast enough to keep your data accurate.

The Bottom Line

Tracking cookies have been the foundation of online marketing for 20 years. They made personalization possible, enabled attribution, helped businesses understand their customers.

But that foundation is crumbling.

Browsers are limiting cookie lifespans. Privacy regulations are tightening consent requirements. Third-party cookies are being phased out entirely.

If you’re still relying on traditional tracking methods, you’re already operating with incomplete data. And the gap is widening every month.

The solution isn’t to give up on tracking. It’s to upgrade to methods that work with modern privacy standards instead of fighting them.

First-party server-side tracking restores the visibility you’ve lost. It captures the visitors standard cookies miss. It gives you accurate data for the long term.

The businesses that adapt now will have a massive advantage over those still waiting for things to go back to normal.

They won’t.

Want to see what your analytics are missing? Learn more about first-party tracking and how it restores complete visibility into your audience.

What Are Tracking Cookies? A Simple Explanation for Website Owners

How Tracking Cookies Actually Work