You've certainly heard the term cookie; not the kind that's crunchy and sweet, but the kind that your web browser uses. Cookies can be useful, because they save information about you. When you revisit a website, you won't have to log in again, because your Mac or iOS device has stored information about your session using cookies. Browser cookies can, however, be nefarious when used in certain ways.
In this tutorial, you'll learn about browser cookies and how to manage them in every major browser on Mac and iOS. I'll also explain what it means to delete your cookies—and why it might be a good idea to do so.
What are browser cookies?
An HTTP cookie, or just cookie for short, is a small bit of text stored on a computer. It stores information about you, or about your activity on a website. It might record your login status, your viewing preferences, the history of what you've viewed, or the contents of a shopping cart. Cookies can make your web browsing more efficient and ensure ads you see online are more relevant to you.
Browser cookies can also have a darker side, depending on your level of privacy needs. Tracking cookies can be used to record all your web activity and send it to central server to build a profile of you and target you with ads. (For example, when you visit Amazon looking for a toilet seat and start seeing ads for toilet seats on other websites.) Some people may see these third-party cookies as helpful, because the ads you see online are more relevant to you. (If you're going to see ads online, wouldn't you rather see ones that are tailored to you?) Others may consider this an invasion of privacy, and, as such, most modern browsers allow you to prevent this type of tracking.
For example, to do this in Safari, go to Safari > Preferences > Privacy and select the checkbox next to "Prevent cross-site tracking." This prevents individual websites from tracking you across the web.
While many cookies are issued by the website you visit, others may also exist when a site uses analytics software (such as Google Analytics) or other trackers, services designed to follow you around on the web.
While you can disable cookies entirely—in Safari, check "Block all cookies" in the preferences shown in the screenshot above—this will break many websites or make them harder to use.
How to manage cookies in all major browsers
If you want to delete your browser cookies, the following guide explains how to do so in every major browser on the Mac. I'll also show you how to remove cookies from Safari on iOS devices.
To manage cookies on Safari, go to Safari > Preferences > Privacy, and then click the "Manage Website Data..." button. This displays a list of all websites that have stored cookies on your computer that can be used to track your browsing. It also shows you any other data that a website stores (such as cached files).
To do this on Firefox, go to Firefox > Preferences, and a new tab will open the Preferences page in your web browser. In the left-hand column, click Privacy & Security, and then under the Cookies and Site Data section click the "Manage Data..." button.
In that dialog popup, you can see which websites store cookies and site data on your computer. As you can see, Firefox will keep this data from websites with persistent storage until you delete it. You can choose to remove all cookies from every website on this list or clear cookies from only selected websites.
To clear your cookies on Google Chrome, go to Chrome > Preferences > Advanced, then, in the Privacy and Security section, click on Clear Browsing Data. You cannot delete individual cookies, as you can with Firefox and Safari, but you can clear cookies and other site data.
And on iOS, you can manage your Safari browser cookies by going to Settings > Safari, and then tap the option to "Clear history and website data." On your iPhone or iPad, you can also choose to "Block All Cookies" under the Privacy & Security section in Safari settings. (For other browsers, check their preferences, settings or help.)
Before you go...
It's unlikely that you'll want to delete an individual cookie, unless you know that a site is behaving incorrectly. However, you may want to use the nuclear option and delete all your cookies. If you'll do this, you'll need to log in again on every website you use, and you may lose some display settings, such as language, currency, text size, and more. But you'll remove any identifying information about you, and when you visit websites, you'll be a new person (to them). Of course, this won't affect sites where you log in to an account; the site will store information about you that doesn't need to be in a cookie, but for other sites, your identity will be refreshed.
That said, it can be a bit of work to have to log in to websites again. If you use a password manager or iCloud Keychain, it will be much simpler to log in again, but if you use two-factor authentication on websites that remember you, you'll need to go through that process again. But this may not be a bad idea—think of it as a kind of spring cleaning for your identity on the Internet.
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