If you've used the internet in the past few years, you've seen countless pop-ups asking you to accept cookies. These notifications have become so ubiquitous that most people click "Accept" without thinking about it. But what are cookies, and why does every website seem to need them?
The answer involves a fundamental problem with how the internet works and an ingenious solution invented in 1994 that has shaped the web ever since.
Cookies aren't the villains that privacy advocates sometimes make them out to be. They're a necessary piece of technology that makes much of the modern web possible. The controversy around them is really about how they've been used, not whether they should exist at all.
The Problem This Was Meant to Solve
The web was built on a protocol called HTTP (Hypertext Transfer Protocol), and HTTP has a peculiar characteristic: it's "stateless." This means that each time you request a page from a website, the server treats it as a completely new interaction. The server has no memory of whether you've visited before, what you clicked on, or anything else about you.
This statelessness was a feature, not a bug—it made the early web simple and scalable. But it created a massive problem for websites that needed to remember things about their users.
Imagine trying to shop online if the website forgot who you were every time you clicked a link. You'd add something to your cart, click to continue shopping, and the cart would be empty. You'd log in, navigate to another page, and suddenly you'd be logged out. The stateless nature of HTTP made these basic functions impossible.
How It Actually Came to Exist
In 1994, a programmer named Lou Montulli at Netscape Communications was working on exactly this problem. Netscape was building one of the first commercial web browsers, and e-commerce companies wanted a way to implement shopping carts.
Montulli borrowed a concept from an older computing technique called "magic cookies"—small pieces of data passed between programs as tokens. He adapted this idea for the web: the server would send a small text file to the user's browser, and the browser would send it back with each subsequent request.
This simple mechanism solved the statelessness problem. The cookie acted as a name tag that the browser showed to the server with each visit. The server could then look up information associated with that tag—your shopping cart, your login status, your preferences—and respond accordingly.
Montulli implemented cookies in Netscape Navigator in 1994, and they were quickly adopted by other browsers. By 1997, cookies were a formal internet standard. The technology spread rapidly because it solved such a fundamental problem.
Why It Still Exists Today
Despite various privacy concerns and alternative technologies, cookies remain essential to the web. They're used for three main purposes: session management, personalization, and tracking.
Session management is the original use case. When you log into a website, a cookie remembers that you're logged in as you navigate from page to page. Without this, you'd have to enter your password on every single page. Shopping carts, saved form data, and game progress all rely on this same mechanism.
Personalization uses cookies to remember your preferences—your language setting, your theme choice, whether you've dismissed a pop-up. This makes websites more convenient to use by eliminating the need to reconfigure settings on every visit.
Tracking is where cookies became controversial. Advertising companies realized they could use cookies to follow users across different websites, building detailed profiles of browsing behavior. This "third-party cookie" use went far beyond the original intention and triggered privacy legislation like GDPR, which requires those annoying consent pop-ups.
What People Misunderstand About It
The biggest misconception is that all cookies are about tracking and surveillance. In reality, most cookies are "first-party" cookies that simply help the website you're visiting function properly. The cookie that keeps you logged into your email is not the same as the cookie that tracks you across the internet for advertising.
Another misconception is that cookies are somehow dangerous files that can harm your computer. Cookies are just plain text—they can't execute code, install malware, or access your files. They can only store small amounts of text data that the website can read later.
Many people also believe that deleting cookies or blocking them entirely will solve privacy problems. While this does prevent tracking, it also breaks many websites. Without cookies, you can't stay logged in, shopping carts don't work, and preferences aren't saved. The solution isn't to eliminate cookies but to regulate how they're used.
Cookies exist because the web needed memory. The original implementation was elegant and solved a real problem. The privacy issues that followed weren't inherent to the technology—they emerged from how advertising companies chose to exploit it. The cookie itself is neutral; it's the usage that can be problematic.