Key Takeaways
Cookies are small text files stored by your browser on behalf of websites. They remember your preferences, login state, and other session data.
First-party cookies are created by the site you visit and generally improve your experience. Third-party cookies are created by external services and are often used for tracking across multiple sites.
Cookies are closely linked to digital identity on the web, allowing sites to recognize and personalize content for returning visitors.
In July 2024, Google reversed its plan to remove third-party cookies from Chrome, opting for a user-choice model instead. Most other major browsers already block third-party cookies by default.
You can manage, limit, or delete cookies through your browser settings to reduce data exposure without breaking most websites.
Introduction
Cookies are small files that websites store on your device through your browser. They are one of the most common ways the web remembers who you are between visits. Whether you're staying logged in, keeping items in a shopping cart, or seeing a site in your preferred language, cookies are often working quietly in the background.
There are different types of cookies, and not all of them are equally benign. Some improve your experience directly. Others collect data about your browsing habits on behalf of advertisers and third-party services. Understanding the difference can help you make more informed choices about your privacy online.
What Is a Cookie?
A cookie is a small text file that a website asks your browser to save on your device. The name traces back to a programming concept called a "magic cookie," popularized by developer Lou Montulli in the early days of the web.
When you visit a website, it may want to remember certain things about you, such as your login status, language preference, or what items you added to a cart. The website sends a cookie to your browser, which stores it.
The next time you visit, your browser sends the cookie back to the site, and the site uses that information to pick up where you left off.
Most cookies are harmless and serve a practical purpose. But the same mechanism can also be used to track your activity across multiple sites, which raises privacy concerns.
Types of Cookies
First-party cookies
A first-party cookie is created by the website you're visiting directly. If you log into a site and your session persists after you close the browser, that's a persistent first-party cookie at work. If it disappears when you close the browser, it is a session cookie.
First-party cookies are widely considered acceptable because their purpose is usually to improve your experience on that specific site. They are not typically shared with other domains.
Third-party cookies
A third-party cookie is set by a domain other than the one you are visiting. Advertising networks, analytics providers, and social media widgets can all embed code into websites that creates these cookies on your device.
Because the same advertiser may have code embedded in hundreds of different sites, their cookies can follow you across the web. This is how behavioral advertising works: a profile of your interests and habits is built over time based on the sites you visit. These are also called tracking cookies.
Other types
Strictly necessary cookies enable basic site functions like shopping carts or secure login areas. Functionality cookies remember your preferences, such as font size or region. Performance or analytics cookies collect aggregate data about how visitors use a site.
What Are Cookies Made Of?
Cookies store data as key-value pairs. A typical cookie might include a session identifier, an expiry timestamp, the issuing domain, and possibly a role or user type. They do not contain executable code; they are plain text files.
You can view the cookies stored in your browser through its developer tools or privacy settings. In Chrome, go to Settings > Privacy and security > Cookies and other site data. In Firefox, go to Preferences > Privacy & Security > Cookies and Site Data. Deleting cookies logs you out of sites and resets stored preferences, but it does not cause permanent harm.
The Dark Side of Cookies
Third-party cookies can expose a significant amount of your browsing behavior to external parties. You may not realize how much data is being collected across multiple sites. This information can be sold or shared, and when combined with other tracking techniques like device fingerprinting, it can be used to build a detailed profile of your online activity.
Data collected through cookies can also be exploited in targeted attacks. Advertisers and data brokers who hold detailed behavioral profiles create opportunities for phishing campaigns tailored to individual users. The more someone knows about you, the more convincing a personalized scam can appear.
Regulations like the General Data Protection Regulation (GDPR) in Europe and the California Consumer Privacy Act (CCPA) in the United States require websites to disclose their cookie use and, in many cases, obtain your consent before placing tracking cookies. This is why cookie consent banners appear on most sites.
Managing your cookies
You can block third-party cookies through your browser settings without significantly affecting your browsing experience. Browsers like Firefox, Safari, and Brave already block them by default. Since 2025, Chrome has offered a user choice experience rather than a blanket block, following Google's July 2024 reversal of its earlier plan to fully deprecate third-party cookies.
Browser extensions like Privacy Badger and uBlock Origin (or uBlock Origin Lite on Chrome) can add an additional layer of control. Regularly clearing cookies and using your browser's private mode for sensitive browsing can also reduce tracking exposure.
FAQ
Are cookies dangerous?
Most cookies are not dangerous. First-party cookies serve legitimate purposes like keeping you logged in. Third-party cookies can raise privacy concerns because they track your behavior across multiple sites, but they do not contain malicious code. The risk is in data collection and profiling, not the cookies themselves.
Can I browse without cookies?
Yes. You can disable all cookies in your browser settings, but this will break many sites: login sessions won't persist, cart contents will reset, and preferences won't be saved. A more practical approach is to allow first-party cookies while blocking third-party ones.
What happened to Google's plan to remove third-party cookies?
Google originally planned to phase out third-party cookies in Chrome by 2022, then pushed the timeline several times. In July 2024, Google reversed course entirely, announcing it would not deprecate third-party cookies. Instead, Chrome now offers a user-choice prompt, letting people decide how cookies are handled across their browsing. Other browsers like Firefox and Safari had already moved ahead with blocking third-party cookies by default.
How do cookies relate to social engineering?
Cookie-based tracking builds behavioral profiles that can be exploited in targeted social engineering attacks. If an attacker or data broker knows your browsing habits, interests, and patterns, they can craft highly personalized phishing messages or scams. This is one reason why minimizing third-party tracking reduces your overall security risk.
Do cookies affect my cryptocurrency accounts?
Session cookies maintain your login state on exchange platforms and wallets. If someone gains access to your active session cookie through a compromised browser or network, they may be able to access your account without needing your password. Using secure, up-to-date browsers and clearing cookies on shared or public devices reduces this risk.
Closing Thoughts
Cookies are a foundational part of how the web works. First-party cookies generally make your experience smoother. Third-party cookies are more contentious, and the landscape around them is still changing. Google's 2024 decision to keep third-party cookies in Chrome, while other browsers moved away from them, means the web remains divided on how to balance functionality with privacy.
Understanding what cookies are and how to manage them puts more control in your hands. Most browsers now offer straightforward tools to limit tracking without disrupting your day-to-day browsing.
Further Reading
Disclaimer: This content is presented to you on an "as is" basis for general information and educational purposes only, without representation or warranty of any kind. It should not be construed as financial, legal, or other professional advice, nor is it intended to recommend the purchase of any specific product or service. You should seek your own advice from appropriate professional advisors. Where the content is contributed by a third-party contributor, please note that those views expressed belong to the third-party contributor, and do not necessarily reflect those of Binance Academy. Digital asset prices can be volatile. The value of your investment may go down or up and you may not get back the amount invested. You are solely responsible for your investment decisions and Binance Academy is not liable for any losses you may incur. For more information, see our Terms of Use, Risk Warning and Binance Academy Terms.