Privacy experts have been talking about web cookies—and how managing them can help boost your online privacy—for a decade or so. But how much do you really know about web cookies and how they affect your online privacy? Are they more trouble than they’re worth? Do they offer anything valuable?
Don’t jump in and start deleting every cookie in your web browser history just yet. First, let’s dig a little deeper into what web cookies are, what they do, and what you need to know about them.
What are Web Cookies and What Do They Do?
An HTTP cookie (web cookie, browser cookie) is a small piece of data that a server sends to a web user's browser. The browser can then store it and send it back with the next request to the same server. Typically, web cookies are used to tell if two requests came from the same browser, which helps the user have more consistent experiences and workflows (by keeping a user logged-in or allowing them to access shopping baskets on an e-commerce site as they shop, for example).
Web cookies are data files and not programs, so they don’t contain malware that has the potential to damage your computer. They’re also very small, only accruing three to 10 kilobytes, which means they don’t take up too much space on your computer either.
Web cookies are usually used for the following reasons:
•Session Management: Cookie files hold information about a user and their online activity for logins, shopping carts, game scores, or anything else a server for a website should remember.
•Personalization: Cookies hold information about a user’s preferences, themes, and other settings.
•Tracking: Cookies are also used to record and analyze user behavior.
Web cookies can ensure you have a seamless and personalized experience while you’re shopping on Amazon, for example—ensuring that you can always access your cart as you shop for items on different parts of the site, and that you can see suggested items based on your recent purchase history and what’s currently available on the site. Sometimes, cookies allow you to come back to a site and pick up where you left off, even if you have closed your web browser.
What's the Problem with Web Cookies?
Here’s where it gets tricky. While being able to access your personalized account on your favorite retailer’s site might seem fine, there are times when third-party sources will track your web browser cookies when you may not be aware of it. This is what makes web cookies such a combative topic in the world of web security. Some people think it’s downright creepy and invasive for another unknown entity (usually an undisclosed third-party advertiser) to track your movements and behavior online, just so they can sell to you elsewhere online without your formal consent.
Here’s how it works. Let’s say you’re shopping for a watch. You go to a retailer’s site and look at watches, but don’t really find what you’re looking for. So, you put your search on hold to visit your favorite blog about skydiving. On the skydiving blog, you notice ads for watches. This occurred because a third-party, such as DoubleClick by Google, was already embedded in code on the watch retailer’s site via their own advertisements. So, while you were on the retailer’s site, the third-party entity hosting ads collected your web cookie files with information about what you were doing and then sent them back to the third-party’s main site. That third-party site then has your web cookie file information, which it can share all over the Internet, wherever their domain’s source code is embedded.
Keep in mind that DoubleClick is only one example of a third-party that can acquire your web cookies.
Which Web Cookies Should I Delete?
The web cookies that allow you to have a seamless experience on a site you log into, or that remember your preferences when you’re playing a game or ordering something, are first-party cookies. They’re unavoidable if you want to have constant access to your favorite accounts like Amazon and Facebook. But you can delete them from your browser history window, and might want to if you have a password manager or have memorized all your passwords for sites you regularly log into.
Third-party cookies, on the other hand, are the cookies that track your movements across the web and allow companies to store information about you, so they can provide you with advertisements and content they think is relevant to you at the right times. Some users don’t mind seeing more targeted ads as they search the Internet and read their favorite blog posts, but others do.
Ultimately, which web cookies you delete is up to you and your individual browsing preferences. All current popular web browsers allow you to block third-party cookies while permitting first-party cookies. Simply go to your web browser’s preferences tab and select your preferred option underneath the available privacy settings.
Regardless of which web cookies you decide to delete or keep, remember that this is only one small piece of the puzzle when it comes to maintaining your web security.