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Zombie Cookies: How They Work and Tips to Prevent Them


Osborn Walter

Jul 4, 2023 | 6 min read
  • Online threats
  • Privacy




Do you know what zombie cookies are ? They are a special type of web tracking technology that can implant persistent cookies in your browser, even if you clear your browser cache and history. This allows websites and advertisers to continuously monitor your internet browsing behavior, collect your personal information and preferences, and even influence the content and prices you see.




How do zombie cookies work?

How to prevent zombie cookies?

Why recommend MetroVPN?


How do zombie cookies work?


Zombie cookies are a technique that utilizes multiple storage locations within the browser to store and restore cookies. Typically, cookies are small text files used to save website identification and settings for you. When you visit a website, it sends a cookie to your browser and requests that it be stored in a specific location such as the hard drive or memory. When you revisit the website, the browser sends back the cookie so that the website knows who you are, along with your preferences and history.


However, zombie cookies go beyond using just one storage location. They exploit other storage mechanisms within the browser, such as Flash Player , Silverlight , HTML5 , ETag , etc., to create multiple copies of the cookie and synchronize them across different locations. This means that even if you delete the cookie from one location, it can be recreated from the remaining locations. This makes zombie cookies very difficult to detect and remove.


How to prevent zombie cookies?


① Disable or restrict third-party cookies in your browser

Third-party cookies come from domains different from the ones you are visiting and are often used for advertising or analytics purposes. You can disable or restrict third-party cookies in your browser settings to prevent unauthorized websites from sending cookies to you.

② Disable or restrict plugins like Flash Player or Silverlight in your browser

These plugins are one of the primary storage mechanisms utilized by zombie cookies. You can disable or restrict these plugins in your browser settings or only allow trusted websites to use them.

③ Use specialized cleaning tools or extensions to remove zombie cookies:

There are professional cleaning tools or browser extensions available that can help detect and remove various types of cookies, including zombie cookies. Examples include CCleaner, BleachBit, BetterPrivacy, etc.

④ Use a VPN to hide your real IP address and location

A VPN (Virtual Private Network) is a service that establishes an encrypted tunnel between you and the internet, preventing your network traffic from being intercepted or tampered with. When using a VPN, you can choose a server location different from your actual region to connect to the internet, thus hiding your real IP address and location, which helps avoid identification and tracking by zombie cookies or other web tracking techniques.


Why recommend MetroVPN?


If you want to use a VPN to block zombie cookies and protect your online privacy and security, I highly recommend using MetroVPN . MetroVPN is an excellent VPN service with the following features and advantages:

① Global servers

MetroVPN has over 5000 high-speed servers located worldwide, allowing you to access any website or content anytime and anywhere, whether they are blocked or restricted.

② Encrypts network activity

MetroVPN encrypts all your network activities, ensuring that your network traffic cannot be eavesdropped or tampered with during transmission, even in insecure environments like public WiFi.

③ Strict no-logs policy

MetroVPN has a strict no-logs policy, meaning it does not record or store any of your network activities or personal information, nor does it share your data with any third parties. This allows you to use the VPN service with complete peace of mind.

④ 24/7 support

MetroVPN has a friendly customer support team available 24/7 to provide professional assistance and solutions to any issues or difficulties you may encounter.

⑤ 30-day money-back guarantee

MetroVPN offers a 30-day money-back guarantee. If you are unsatisfied with MetroVPN within 30 days, you can request a full refund without any reasons needed.


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