On websites, cookies are ubiquitous and often essential for the smooth functioning of these websites. These small text files store important information about your activities and preferences, enable personalized experiences, and help the website operator analyze your behavior on the website. In this article, you will learn how to delete, block and manage cookies in Chrome, Firefox, Safari and Edge on your Mac, Windows PC, iPhone or Android smartphone.
Cookies are small text files that store information on your device and can be read by the website when required. They perform various functions, ranging from ensuring basic website functionalities to collecting and analyzing user data. It is important to differentiate between technically necessary and technically unnecessary cookies.
Technically necessary cookies are essential for the proper functioning of the website. They store information that is absolutely necessary for the use of the website. A classic example of this is the storage of your login status on a website, as otherwise you would have to log in again each time you visit a subpage. Similarly, your shopping cart in online stores is often managed in technically necessary cookies. Without these cookies, the website would not function correctly, as they enable basic functions and security measures.
Technically non-essential cookies, on the other hand, are not absolutely necessary for the website, but can improve your user experience and marketing measures. These cookies are used, for example, to track and analyze your user behavior. By analyzing how you as a user interact with the website, operators can gain valuable insights that help to optimize the website and increase the efficiency of marketing campaigns. Another example is cookies that are used to personalize content and advertising so that content tailored to you or targeted advertising can be displayed.
Another important distinction is between so-called first-party cookies and third-party cookies. First-party cookies can only be read and written on the website you are visiting. Such cookies are usually set and read by the tools or plugins used on the website. Third-party cookies, on the other hand, come from external tools and their domains that are integrated on the website you are visiting, for example through advertisements or social media plugins. These cookies enable third-party providers to collect user data from you and to read and process it on other websites that use a tool from the same provider. Third-party cookies are criticized because they can be used to create extensive user profiles. Mozilla Firefox (since June 2019) Apple Safari (since April 2020) therefore blocks all third-party cookies by default.
On the one hand, cookies enable an improved user experience, as you can be recognized as a returning user and your preferences can be stored. In addition, website performance and marketing measures can be made more efficient through cookies and the data collected as a result. On the other hand, there are also disadvantages for you as a website visitor, as the storage and processing of data is not always implemented in compliance with data protection regulations, and there is a risk of misuse, especially when using third-party cookies. In addition, blocking cookies can impair the functionality of the website, which can lead to errors on the website.
Information can technically be stored in various ways, which are usually summarized under the term cookies. The best known examples of this are HTTP cookies, local storage, session storage or IndexedDB. Each type of storage has different properties, which determine the technical handling, accessibility and authorized access to the information.
- HTTP cookies are small data sets that are stored on the user’s device. They can store session data, user preferences and tracking information. These cookies are automatically transferred to the server with every HTTP request from the browser, as long as the cookie domain and path match. The validity period of cookies varies: session cookies are deleted when the browser is closed, while persistent cookies have a fixed expiration date defined by the cookie’s creator. The access authorization to cookies is determined by the cookie domain and can be further controlled by setting the attributes HttpOnly, Secure und SameSite, so that access to the cookies can be prevented by JavaScript and their transmission can be restricted to secure connections.
- Local storage offers a way to store large amounts of data in the browser for the long term. This data is retained even after the browser is closed and is ideal for storing user preferences, configuration data or temporary storage of form content. In contrast to HTTP cookies, data in local storage is not automatically transferred with HTTP requests, but remains locally in the browser and must be explicitly transferred to the server. Information in local storage remains until it is explicitly deleted by the user or the application, and therefore has no set expiry time. Access to the data stored in Local Storage is via JavaScript and is restricted to the web applications that belong to the same domain as the data.
- Session storage offers a way to temporarily store data in the browser. This data is retained even after the page is reloaded, but only during the current session and is deleted as soon as the browser or the corresponding tab is closed. Session storage is ideal for storing temporary user input or navigation states that are only required during the current session. In contrast to HTTP cookies, data in session storage is not automatically transferred with HTTP requests, but remains locally in the browser and must be explicitly transferred to the server. Access to the data stored in session storage is via JavaScript and is restricted to the web applications that belong to the same domain as the data.
- IndexedDB is a powerful storage method for complex and large amounts of data in the browser, which makes it possible to store structured data. This storage method is useful for web applications with offline functionality or extensive databases. Unlike HTTP cookies, IndexedDB is not automatically transferred with HTTP requests, but remains stored locally in the browser. The information in IndexedDB has no fixed validity period and remains until it is explicitly deleted. The data stored in IndexedDB is accessed via JavaScript, whereby access is restricted to the same domain.
The topic of cookies is not only relevant from a technical point of view, but also from a data protection perspective:
- ePrivacy Directive (regulates the integrity of the user device): This directive and the associated laws in the member countries require the active consent of visitors for non-essential cookies. Essential cookies, which are necessary for the operation of the website, do not require consent, but must be mentioned in the privacy policy or in the cookie banner.
- GDPR (regulates the handling of personal data): In order to process personal data, you need a legal basis in accordance with Art. 6 GDPR. In many cases, consent is the only option, as some cookies process personal data directly, e.g. a user ID, a name or an email address, or they contain so much information that they could theoretically be indirectly assigned to a person. In addition, you must provide detailed information about the data processing and everything associated with it (Art. 13 GDPR).
Setting up cookie banners correctly is crucial, but not all websites implement the legal requirements correctly. A consent management solution such as Real Cookie Banner for WordPress can help website operators to implement data protection requirements correctly.
In addition to data protection concerns, cookies are often the cause of problems such as slow loading times or unwanted advertising. Deleting cookies can help improve browser speed and protect your privacy. Here is a step-by-step guide on how to delete cookies in the most popular browsers.
There are various ways to delete cookies in Google Chrome:
- Delete all cookies: In your browser, click on the 3 vertical dots in the top right-hand corner of your browser to go to Settings > Privacy and security > Delete browsing data. Here you can now adjust the time range for which you want to delete “Cookies and other site data” to “All time” and, if necessary, remove the automatically set checkmarks for “Browsing history” and “Cached Images and files” if you do not want this data to be deleted as well. Then click on “Delete data” to delete all cookies.
- One website: Open the developer console (right-click on open website > Inspect > Application > Storage), select the “including third-party cookies” checkbox and press “Clear site data” to delete all cookies on this website and third-party cookies from integrated tools.
- Individual cookies: Open the developer console (right-click on open website > Inspect > Application > Cookies / Session Storage / Local Storage), select the cookie you want to delete by right-clicking on it and press “Delete” to delete this individual cookie. This step can be performed for cookies as well as in session storage and local storage.
There are various ways to delete cookies in Mozilla Firefox:
- Delete all cookies: In your browser, click on the 3 horizontal lines in the top right-hand corner and go to Settings > Privacy & Security > Cookies and Site Data > Manage data. Now select “Remove All”, click on “Save Changes” and confirm your selection in the next dialog with “Clear Now”.
- One website: In your browser, click on the 3 horizontal lines in the top right-hand corner and go to Settings > Privacy & Security > Cookies and Site Data > Manage data. Now select the desired website and click on “Remove Selected”, then click on “Save changes” and confirm your selection in the next dialog with “Clear Now”.
- Individual cookies: Open the developer console (right-click on open website > Inspect > Storage > Cookies / Session Storage / Local Storage), select the desired cookie by right-clicking and press “Delete [cookie name]” to delete the cookie on this website. This step can be performed for cookies as well as in session storage and local storage.
In Microsoft Edge, proceed as follows to delete cookies in various ways:
- Delete all cookies: In your browser, click on the 3 horizontal dots in the top right-hand corner of your browser go to Settings > Privacy, Search, and Services > Delete browsing data > Choose what to Clear. Now you can adjust the period for which you want to delete the cookies and other website data to “All Time” and, if necessary, remove the automatically set checkmarks for “Browsing history”, “Download history” and “Cached images and files” if you do not want this data to be deleted as well. Then click on “Clear now” to delete all cookies.
- One website: Open the developer console (right-click on open website > Inspect > Application > Storage), select the “including third-party cookies” checkbox and press “Clear site data” to delete all cookies on this website and third-party cookies from integrated tools.
- Individual cookies: Open the developer console (right-click on open website > Inspect > Application > Cookies / Session Storage / Local Storage), select the cookie you want to delete by right-clicking on it and press “Delete” to delete this individual cookie. This step can be performed for cookies as well as in session storage and local storage.
There are various ways to delete cookies in Safari:
- Delete all cookies: Go to Safari in the top bar of your screen and go to Settings > Privacy. Then click on “Manage Website Data…”, then press “Remove all” and confirm your selection in the next dialog to delete all cookies.
- One website: Go to Safari in the top bar of your screen and go to Settings > Privacy. Then click on “Manage Website Data…”, click on the requested website and press “Remove” to delete all cookies for this website.
- Individual cookies: Before you can delete individual cookies on a website, the developer console must be activated in your browser. Go to Safari in the top bar of your screen and go to Settings > Advanced and activate “Show features for web developers”. Now open the developer console (right-click on open website > Inspect Element > Storage > Cookies / Session Storage / Local Storage) and select the desired cookie by right-clicking on it and press “Delete” to delete the cookie.
On an Android device, you can delete cookies in Google Chrome as follows
- Delete all cookies: In your browser, use the vertical dots to go to Settings > Privacy and security > Delete browsing data. Here you can adjust the period for which you want to delete the “Cookies and website data” to “All time” and, if necessary, remove the automatically set checkmarks from the other checkboxes if you do not want this data to be deleted as well. Then click on “Delete data” and confirm your selection by clicking on “Delete”. This step can be carried out for cookies as well as in session storage and local storage.
This is how you delete cookies in Safari on an iPhone:
- Delete all cookies: Go to Settings (App) > Safari > Privacy & Security, press “Clear history and Website Data” and confirm the selection by pressing “Clear history”.
How can you clear the cache in different browsers?
The cache stores temporary data to load websites faster. If the cache is damaged or contains outdated data, this can lead to problems when loading websites. Clearing the cache regularly can help to resolve these issues. Here’s how you can clear the cache in the most popular browsers:
Google Chrome: How can you clear the cache?
- Empty the cache: In your browser, click on the 3 vertical dots in the top right-hand corner of your browser to go to Settings > Privacy and security > Delete browsing data. Now you can adjust the time range for which you want to clear “Cached images and files” to “All time” and, if necessary, remove the automatically set checkmarks for “Browsing history” and “Cookies and other site data” if you do not want this data to be deleted as well. Then click on “Delete data” to empty the cache.
- One website: Open the developer console (right-click on open website > Inspect > Application > Storage), select the check mark for “Cache storage” under Storage at the bottom of the Developer Console, uncheck the other boxes if you don’t want to delete this information, and press “Clear site data” to clear the cache for this website.
Mozilla Firefox: How can you clear the cache?
- Empty the cache: In your browser, click on the 3 horizontal lines in the top right-hand corner and go to Settings > Privacy & Security > Cookies and Site Data > Clear data. Now you can adjust the period for which you want to clear “Temporary cached files and pages” to “Everything” and, if necessary, remove the automatically set check mark for “Cookies and site data” if you do not want this data to be deleted as well. Then click on “Clear” to empty the cache.
- A website: In your browser, click on the 3 horizontal lines in the top right-hand corner and go to History > Manage history. Select the desired website using the search function in the top right-hand corner, right-click on the desired website and click on “Forget about this Site…” to clear the cache for this website.
Microsoft Edge: How can you clear the cache?
- Empty the cache: In your browser, click on the 3 horizontal dots in the top right-hand corner of your browser go to Settings > Privacy, Search, and Services > Delete browsing data > Choose what to Clear. Now you can adjust the period for which you want to delete the cache (“Cached images and files”) to “All Time” and, if necessary, remove the automatically set checkmarks for “Browsing history”, “Download history” and “Cookies and other site data” if you do not want this data to be deleted as well. Then click on “Clear now” to clear the cache.
- One website: Open the developer console (right-click on open website > Inspect > Application > Storage), and press “Clear site data” to clear the cache for this website.
Apple Safari: How can you clear the cache?
- Empty cache: Before you can clear the cache for a website, the developer console must be activated in your browser. Go to Safari in the top bar of your screen and go to Settings > Advanced and activate “Show features for web developers”. Now click on Develop > Empty Caches in the top bar of your screen to clear the entire cache.
On Android with Google Chrome: How can you clear the cache?
- Empty the cache: In your browser, use the vertical dots to go to Settings > Privacy and security > Delete browsing data. Here you can now adjust the period for which you want to delete “Images and files in the cache” to “Total time” and then click on “Delete data”.
On iPhone (iOS) with Apple Safari: How can you clear the cache?
- Clear cache: Go to Settings (App) > Safari > Privacy & Security, press “Clear History and Website Data”, select a time frame for which you want to clear the cache, and confirm the selection by pressing “Clear History”. In addition to the cache, this also deletes cookies, local storage, session storage, etc.
Managing cookies is crucial for protecting your privacy when surfing the internet. Proper management helps you to block unwanted cookies and protect important data. Here you can find out how to manage cookies in the most important browsers:
- Activate/deactivate cookies: In your browser, click on the 3 vertical dots in the top right-hand corner of your browser to go to Settings > Privacy and security > Site settings. Now click on “Additional content settings” under the heading “Content” to be able to make settings for the storage of cookies under “On-device site data” and to deactivate the setting of cookies in general by checking the box “Don’t allow sites to save data on your device (not recommended)”. In addition, all cookies can be deleted automatically when the browser is closed, thus deactivating long-term tracking by cookies.
- Add exceptions: In your browser, click on the 3 vertical dots in the top right-hand corner of your browser to go to Settings > Privacy and security > Site settings. Now click on “Additional content settings” under the heading “Content” to be able to make settings for the storage of cookies under “On-device site data”. On “Customised behaviours”, you can add exceptions via “Add” to exclude certain websites from your cookie settings.
- Activate/deactivate cookies: In your browser, click on the 3 horizontal lines in the top right-hand corner and go to Settings > Privacy & Security > Browser Privacy > Enhanced Tracking Protection. Here you must set the selection to “Custom”, then check the “Cookies” box, and you can then select “All cookies (will cause website to break)” or another setting of your choice to prevent cookies from being set.
- Add exceptions: In your browser, click on the 3 horizontal lines in the top right-hand corner and go to Settings > Privacy & Security > Browser Privacy > Enhanced Tracking Protection > Manage Exceptions. Now you can add exceptions to exclude certain websites from your cookie settings.
- Activate/deactivate cookies: In your browser, click on the 3 horizontal dots in the top right-hand corner of your browser go to Settings > Cookies and Site Permissions > Manage and delete cookies and site data. Here you can make specific settings for cookies, view all website data and authorizations and prevent certain cookies from being set. In addition, all cookies can be deleted automatically when the browser is closed, which means that long-term tracking by cookies can be deactivated.
- Add exceptions: In your browser, click on the 3 horizontal dots in the top right-hand corner of your browser go to Settings > Cookies and Site Permissions > Manage and delete cookies and site data. Here you can add exceptions to “Block”, “Allow” or “Clear on exit” to define specific websites on which you want to change the use of cookies and website data.
- Activate/deactivate cookies: Go to Safari in the top bar of your screen and go to Settings > Advanced. There, at “Privacy”, you will find the option “Block all cookies” , which deactivates cookies in your browser.
Use the red arrow at the top right of your browser to go to Settings > Site settings > Cookies. Here you can make specific settings for cookies and also define exceptions for specific websites.
Go to Settings (App) > Safari > Advanced. Here you can adjust the cookie settings in the “Privacy” section.
Blocking cookies can help reduce the amount of data collected about your browsing behavior and protect your privacy. At the same time, however, blocking all cookies means that many websites will no longer function correctly, which is why you should be careful with this setting. The exact steps for blocking cookies vary from browser to browser. Here you can find out how to block cookies in the most important browsers:
- Block all cookies: In your browser, click on the 3 vertical dots in the top right-hand corner of your browser to go to Settings > Privacy and security > Site settings. Now click on “Additional content settings” under the heading “Content” to be able to make settings for the storage of cookies under “On-device site data” and to block the setting of cookies in general by checking the box “Don’t allow sites to save data on your device (not recommended)”.
- Block all cookies: In your browser, click on the 3 horizontal lines in the top right-hand corner and go to Settings > Privacy & Security > Browser Privacy > Enhanced Tracking Protection. Here you must set the selection to “Custom”, then check the “Cookies” box, and you can then select “All cookies (will cause website to break)” to block cookies completely.
- Block cookies on certain websites: In your browser, click on the 3 horizontal lines in the top right-hand corner and go to Settings > Privacy & Security > Cookies and Site Data > Manage Exceptions. Here you can define specific websites on which you want to block the use of cookies and website data.
- Block all cookies: In your browser, click on the 3 horizontal dots in the top right-hand corner of your browser go to Settings > Cookies and Site Permissions > Manage and delete cookies and site data. Here you must uncheck the box “Allow sites to save and read cookie data (recommended)” to block cookies in your browser.
- Block cookies on certain websites: In your browser, click on the 3 horizontal dots in the top right-hand corner of your browser go to Settings > Cookies and Site Permissions > Manage and delete cookies and site data. Under “Block”, you can define individual websites on which cookies should be blocked.
- Block all cookies: Go to Safari in the top bar of your screen and go to Settings > Advanced. Then, at “Privacy”, activate “Block all cookies” to block cookies in your browser.
- Use the red arrow at the top right of your browser to go to Settings > Site settings > Cookies. Here you can select “Block all cookies (not recommended)” to block cookies.
- Go to Settings (App) > Safari > Advanced and activate “Block All Cookies”.
Blocking certain cookies is an important step in protecting your online privacy, but there are also other technical ways in which website operators can carry out tracking or similar. Server-side tracking, for example, allows websites to store data on their servers without you being aware of it and independently of the cookies set. Web beacons or pixels can also be used to track your behavior using integrated invisible graphics, while fingerprinting techniques are used to identify you through a combination of device characteristics. These methods are often more difficult to prevent and can still be used by website operators to collect data about your surfing behavior.
The use of adblockers such as uBlock Origin is an effective method of taking targeted action against unwanted cookies or further data processing. Such an adblocker offers various filter lists that allow you to block specific services and their content. This includes advertising, analysis and tracking services, the integration of social networks and annoying content such as pop-ups and overlays. By customizing these filter lists, you can specifically prevent unwanted cookies from being stored on your device and thus effectively protect your privacy.