What is a Cookie & How Do Cookies Work?
A complete guide to understanding browser cookies, how they track you, and how to manage them effectively for better privacy and security.
Table of Contents
What Are Internet Cookies?
Cookies (also known as internet cookies or browser cookies) are small text files containing pieces of data—like usernames, preferences, or session IDs—that websites store on your device. They help identify your computer and personalize your web browsing experience.
When you visit a website, the server creates cookie data labeled with a unique ID for you and your device. This ID allows the server to recognize you and serve personalized content on future visits.
Privacy Note: Due to laws like GDPR (EU) and CCPA (California), websites must now ask permission to use certain cookies and explain how they'll be used.
Magic Cookies
An old computing term referring to packets of information sent and received without data changes. Originally used for database logins in internal networks—predating modern browser cookies.
HTTP Cookies
Created in 1994 by Lou Montulli, HTTP cookies are the modern version we use today. They enable personalized web experiences but can also be exploited by cybercriminals to track activity and steal information.
What Are Tracking Cookies?
Tracking cookies are small text files that websites place on your browser to collect data about your online activities. These files contain data that allows websites to remember specific user preferences, maintain login sessions, and track user behavior across different sites.
They store information such as geographic location, device specifications, and specific actions taken on websites. The primary purpose of tracking cookies is to enable personalized experiences, targeted advertising, and website analytics.
Important: Tracking cookies can be categorized into first-party cookies (set by the website you're visiting) and third-party cookies (created by external services or advertisers).
How Browser Tracking Cookies Are Used
Tracking cookies are widely used by businesses for various purposes. Here are common examples:
Ecommerce Personalization
Tracking cookies remember browsing history and purchase preferences, allowing websites to recommend relevant products, offer personalized discounts, and streamline the purchasing process.
Ad Targeting
Advertisers use tracking cookies to deliver targeted advertisements based on user interests and browsing behavior. For example, frequent visits to travel websites may result in ads for vacation packages or flight deals.
Analytics and Optimization
Tracking cookies provide valuable data for website owners to identify trends and optimize site performance. Businesses can see which products are most viewed and purchased, helping understand user interaction patterns.
Social Media Integration
Many websites use tracking cookies through social media plugins to enable content sharing or social media logins. These cookies personalize the website experience based on social media preferences and activities.
What Are HTTP Cookies?
HTTP cookies, or internet cookies, are built specifically for web browsers to track, personalize and save information about each user's session. A "session" refers to the time you spend on a website.
Cookies are created to identify you when you visit a new website. The web server sends a short stream of identifying information to your web browser in the form of cookies. This data is processed and read by "name-value" pairs that tell the cookies where to be sent and what data to recall.
You hand over your "coat" to the cloak desk
You connect/visit a website and a pocket of data is linked to you on the website's server. This data can be your personal account, shopping cart, or pages you've visited.
You get a "ticket" to identify you as the owner
The cookie (containing the data) is then given to you and stored in your web browser. It has a unique ID especially for you.
You can get the "coat" back with your "ticket"
When you revisit the website, your browser gives the cookie back. The website reads the unique ID to assemble your activity data, bringing you back to where you were, as if you never left.
What Are the Different Types of HTTP Cookies?
With a few variations, cookies in the cyber world essentially come in two main types: session cookies and persistent cookies.
Session Cookies
Temporary cookies that are deleted when you close your browser. They're used to remember your actions during a single browsing session, like items in your shopping cart.
Persistent Cookies
Long-term cookies that remain on your device even after you close your browser. They're used to remember your login credentials and preferences for future visits.
How to Manage and Delete Cookies
Take control of your privacy by managing cookies effectively
Manual Deletion
Clear cookies through your browser settings
Automatic Cleaning
Use tools to schedule regular cookie deletion
Selective Control
Keep important cookies, delete tracking ones
Frequently Asked Questions
Common questions about browser cookies answered
Q.What is a cookie in simple terms?
A cookie is a small text file that websites store on your device to remember information about you, such as your login status, preferences, and browsing activity.
Q.Are cookies dangerous?
Most cookies are harmless and necessary for websites to function properly. However, tracking cookies can collect your browsing data across multiple sites, which raises privacy concerns. It's recommended to regularly clear cookies and use privacy tools.
Q.Should I delete cookies?
Yes, regularly deleting cookies can improve your privacy, free up storage space, and fix website issues. You can use tools like Broom Cookie Cleaner to automatically manage and delete cookies on a schedule.
Q.What's the difference between first-party and third-party cookies?
First-party cookies are created by the website you're visiting and help with functionality like keeping you logged in. Third-party cookies are created by external services (like advertisers) and track your activity across multiple websites.
Q.How do I block third-party cookies?
Most modern browsers allow you to block third-party cookies in their privacy settings. You can also use browser extensions like Broom Cookie Cleaner for more granular control over which cookies are allowed.
Q.Will deleting cookies log me out of websites?
Yes, deleting cookies will log you out of most websites since they use cookies to maintain your login session. However, you can use selective cookie management tools to keep login cookies while deleting tracking cookies.