Understanding Browser Cookies: A Guide

When you clicked on this blog, you most likely got a pop-up at the bottom of the page that read something that said: We value your privacy. We use cookies to enhance your browsing experience, serve personalized ads or content, and analyze our traffic.

By instinct, you probably clicked “Accept All” just to get rid of it. Have you ever thought about what it means or why it is asking you to Accept All? Sure, you may have heard of browser cookies before but did you ever think about what they are?

A cookie or a browser cookie is a small piece of data that a server sends to your browser. The browser may store cookies, create new ones, modify existing ones, or send them back to the same server with later requests. Browser cookies allow web applications to store limited amounts of data and remember information about you and your preferences.

In this article, we will be exploring everything there is to know about browser cookies, telling you what they are, how they work, and how you can get rid of them.

What Are Browser Cookies?

A browser cookie (or an HTTP cookie) is a tiny snippet of data or code that is stored on a web browser whenever you visit a website. It contains information about your activity on the website like your preferences, login status, and shopping cart contents. The next time you visit the website, it will recognize the cookie and ingest the stored data. These browser cookies can either be stored for a specific amount of time or for the length of your session on the website.

The browser cookie’s data is labeled with an ID that is unique to you and your device. When the cookie is exchanged between your computer and network server, the server reads the ID and knows what information to serve to you specifically.

Due to international laws such as the EU’s General Data Protection Regulation (GDPR) and specific US state laws like California Consumer Privacy Act (CCPA), most websites are legally required to ask for permission to use certain cookies with your browser, with details of why the browser cookie is being collected. If you have already accepted Proxidize’s cookies, you can open this article in an incognito page to learn about the cookies that we collect.

Types of Browser Cookies

There are several different types of browser cookies, each with its own feature and reasoning. While some cookies are optional, there are a few cookie types that cannot be turned off as they may affect how the website functions.

Session Cookies

These cookies are temporary and are stored on a device only during the actual browsing session. They maintain information while you are accessing the website and get deleted when you close the browser.

Session cookies are stored in your random access memory and never written in the hard drive itself. Most commonly, the session cookies are used for maintaining the continuity of your browser session and keeping track of your activity on a website, remembering your actions as you navigate the website. Session cookies help keep items in your shopping cart as you navigate from page to page. This does not mean that when you close out the tab or browser and return, the cart will remember your items. It simply keeps the memory as you navigate pages.

Persistent Cookies

These types of browser cookies remain on your device even after you close your browser. They have expiration dates and are only deleted when that date comes to fruition. While they do contain an expiration date, this can be anything from a day, a week, to several months or years.

These browser cookies are used to store information for future visits like your login credentials and other personal identifiers. Aside from keeping your login information saved, persistent cookies are also used for tracking purposes by the website you are visiting. They will see what pages or items you showed interest in and suggest similar items for you.

Authentication Cookies

These cookies help manage user sessions and are generated when you log into an account through the browser. They ensure that sensitive information is delivered to the correct user sessions by associating user account information with a cookie identifier string.

Zombie Cookies

Often used by advertising network and analytics companies, zombie cookies track online behavior and deliver targeted ads. Due to their difficulty of being removed once saved, zombie cookies are also sometimes called super cookies. They are used to create long-term profiles on users to get a more full picture of your activities online.

They are difficult to delete because they are often stored in multiple locations including Flash Local Shared Objects, HTML5 Web Storage, and other browser plugins. Of all the browser cookies, zombies hold the biggest privacy concerns because they can track your browsing activity across multiple websites and devices.

Party Cookies

There are two types of party cookies which are first-party and second-party. First party browser cookies are accessed and used only by the website that created them while third-party browser cookies are used by advertising networks to track the browsing history of a user.

First-party cookies are safer than third-party ones because they are more open and honest about what they are doing. As long as the website you are visiting is reputable and has not been compromised by a data breach or cyberattack.

First-parties are used to provide a good user experience, collect any analytic data, remember language settings, your account settings, and any personalized content. This is done to remember your choices so that the next time you visit, the website will be bespoke to you.

Third-party cookies are generally why people get worried when they see browser cookies. While first-parties are related to the general functionality and customization of your experiences on the website, third-party cookies are linked to the advertisements on the website and follow you throughout your entire browsing experience.

They let advertisers or analytics companies track your browsing history across the web on any website that contains their ads. This allows them to create a user profile of you so they can show you ads of things you have searched before. If you visited Website 1 and clicked on an advertisement for a bookshelf, by the time you visit Website 5, you might see an advertisement for another bookshelf in an attempt to reel you back to the advertiser.

However, with the data protection laws we mentioned earlier, allowing third-party cookies is optional in many countries and states and can sometimes be the only options you can opt out of when accepting cookies in general. In 2024, Google announced an end to third-party cookies on its flagship browser Chrome, however many other browsers are yet to follow that method.

What Are Cookies Used For?

Browser cookies are used by the web server to differentiate between different requests depending on the browser or user. It does this to issue a personalized response following the user’s first visit, providing them with their preferred language settings and brightness specification. A simple step by step process of how it does this is as follows:

1. The user sends sign-in credentials to the server through a form submission.
2. If the credentials provided are correct, the server updates the UI to indicate the user has signed in and responded with a cookie that contains a session ID that records their sign-in status on the browser. If the login credentials are incorrect, then the user is likely facing an error code 401.
3. If and when a user moves to a different page on the same website, the browser will send the cookie containing the session ID along with the corresponding request to let it know that the user is still signed in.
4. The server will check the session ID and if it finds it valid, it will send the user a personalized version of the new page. If it is not valid, the session ID will be deleted and the user will be shown a generic version of the page.

Browser cookies exist for three main reasons; session management, personalization, and tracking. For session management, it keeps track of sign-in status, shopping card contents, game scores, or other session-related details that need remembering. It personalizes display language and any UI themes (dark mode or light mode). As we stated, it tracks user behavior, mostly for marketing purposes.

To better understand how browser cookies work across a user’s journey, let us create a person and call him John Smith. John has an account at Home Depot that he uses for his woodworking needs. When John logs into Home Depot, the website’s server generates a session cookie and sends the cookie to John’s browser. This cookie will tell the website to load John’s account content so the homepage will now read “Welcome John”.

When John clicks on a product page, his browser will send an HTTP request to the website for the product’s page which includes his session cookie with the request. The request will recognize the user as John and he does not need to log in again when the new page loads.

If he decides to log out of the Home Depot website, his username can be stored in a cookie and sent to his browser. The next time he decides to load the website, his browser will send this cookie to the web server which will prompt John to log in with the username he used last time.

If John visited a website that sent his browser a tracking cookie, this cookie may record that John is viewing a product page. The next time he loads a website that uses this tracking service, he might see ads for the same product he clicked on.

How to Clear Browser Cache and Cookies

If you wish to clear your browser cookies, either to always have a fresh set, reload the advertisement preference, or to bypass a proxy error code, this section will show you how to clear your cookies on all the major browsers available.

Microsoft Edge

1. Click on the three dots in the upper-right corner of the browser window and select Settings.
2. On the Settings page, select Privacy, Search, and Services, and scroll down to Clear Browsing Data and select which data you wish to clear.

Google Chrome

1. Click on the three dots in the upper-right corner and select Settings.
2. In the Settings window, select Privacy and Security, scroll down to Clear Browsing Data, and select the Cookie and Other Site Data checkbox.

Macintosh Safari

1. Click Safari in the upper-left corner and click on Settings.
2. Click the Privacy tab and then on Manage Website Data.
3. Select Remove or Remove All to clear all cookies.

Mozilla Firefox

1. Open the three-lines menu in the upper-right corner and select History.
2. Open the Clear Recent History tab. Select the time period you would like to erase.
3. Check the box next to Cookies and Site Data and leave all other options unchecked.

Opera GX

1. Use the shortcut Ctrl + H to open the browsing history and click Clear Browsing Data in the upper-right corner of the pop-up screen.
2. Select the time range you would like to clear and check the box for Cookies and Other Site Data.

Disable Cookies in Browser

If you wish to block browser cookies entirely, either because you do not mind having to log back into each website or you have a distrust of cookies, here is how you can block cookies on Edge, Chrome, Safari, Firefox, and Opera.

Microsoft Edge

1. Click on the menu icon on the upper-right corner and select Settings.
2. Select Cookies and Site Permissions. Click on Manage and Delete Cookies and Site Data.
3. Under Cookies and Data Stored, disable Allow Sites to Save and Read Cookie Data.

To block third-party cookies:

1. Under the Cookies and Site Permissions tab, open Manage and Delete Cookies and Site Data.
2. Under Cookies and Data Stored, enable Block Third-Party Cookies.

Google Chrome

1. Click on the upper-right corner and select Settings.
2. Select Privacy and Security and click on Cookies and Other Site Data.
3. Under General Setting, select Block All Cookies.

To block third-party cookies:

1. Under Privacy and Security, click on Cookies and Other Site Data.
2. Under General Settings, find the option to enable Block Third-Party Cookies.

Macintosh Safari

1. Select Safari and click Preferences.
2. In the Privacy tab, enable Block All Cookies. In the pop up that follows, select Block All.

Luckily, Safari already blocks third-party cookies with the Prevent Cross-Site Tracking feature enabled.

Mozilla Firefox

1. Click on the upper-right corner and select Settings.
2. Click on Privacy & Security on the left sidebar. Under Enhanced Tracking Protection, select Custom.
3. In the Cookies dropdown list, select from multiple options to disable cookies.

Much like Safari, Firefox blocks third-party cookies by default.

Opera GX

1. Open Settings by clicking on the Opera GX logo in the upper-left corner or press Alt+P.
2. Click on Privacy & Security. Click on Site Settings (or Cookies and Site Data).
3. Turn off the toggle for Allow sites to save and read cookie data.
4. You should also see an option to block third-party cookies within the same menu.

A few other ways you can prevent cookies from being stored on your machine include using Incognito Mode as it will prevent search history and cookies from sticking to your computer. You can also use a proxy server to keep your identity anonymous as all requests will go through the server rather than directly to the website. 

Proxies can be configured to block or remove cookies by removing the cookie header from a request before forwarding it to the website. You can also use a browser extension that you can turn on and off for specific websites to help you manage or stop cookies.

Another way to prevent cookies from being stored on your device and preventing advertisers from learning too much or anything about you is by using antidetect browsers which, as the name suggests, prevents any detection of you or your activity from happening.

Conclusion

Browser cookies are nothing to be afraid of. On the contrary, they are there to make your browsing experience easier and run smoother. Cookies make it easier for you to log back into a website and see all your preferences such as language and UI set, it keeps items in your cart as you navigate through the website, and can help a website and its advertisers bespoke content to you.

Key takeaways:

1. Browser cookies are little lines of code that attach to your browser and help customize a website to your preferences and interests.
2. There are five major types of cookies, each with their own reasons for existing and different functions. Some types are helpful to your experience as a whole while others are optional to help the website function better.
3. Laws such as the GDPR and CCPA are set to battle harmful cookies and prevent websites from taking every bit of information about customers.
4. Web browsers such as Safari and Firefox have outright banned the use of third-party browser cookies, which are the type that follow you throughout every website you visit and build a profile on you so that advertisers can drop ads for your interests on any website.
5. Some way you can prevent browser cookies from taking effect is by using an incognito tab, implementing a proxy server, or even using an antidetect browser.

While that may sound like a great thing for most, others might be hesitant to have a website know everything or anything about them. Which is why this article has provided insights into how you can remove browser cookies or even outright block them from knowing anything about you. 

As always, browser cookies are optional and every website that tracks them will need to ask your permission before attaching the bit of code onto your browser. You can always opt out of them before you accept and if you decide you no longer want the browser cookies, this guide will show you how you can delete and block cookies.

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