Fingerprinting is a digital tracking technique that allows websites to identify a user via the technical characteristics of their browser, without using cookies.
Fingerprinting is a probabilistic technique that aims to uniquely identify a user on a website or mobile application by using the technical characteristics of their browser. Unlike cookies, this method does not store any files on your device.
Browser fingerprinting automatically collects thirteen key attributes via your web browser. HTTP headers transmit your user agent, revealing your operating system and browser version. JavaScript APIs access system information via the window.screen and window.navigator objects.
Your browser reveals several discriminating pieces of information:
Canvas fingerprinting generates a unique visual fingerprint based on your graphics hardware. This technique exploits differences in rendering between graphics cards and drivers to create a stable identifier.
Fingerprinting scripts collect this information without your explicit consent. According to the CNIL, this collection requires prior informed consent. However, many websites continue to use this method to track internet users.
This technique allows users to be identified even when cookies are blocked, creating a persistent digital fingerprint that tracks your online movements without leaving any detectable traces on your system.
Websites collect 13 key attributes to create your unique digital fingerprint. This technical information reveals your identity without leaving any traces on your device.
Your browser automatically transmits the user agent via HTTP headers. This data reveals your operating system, browser version, and sometimes the exact model of your device. Chrome on Android exposes more information than Firefox, which uses a generic user agent.
JavaScript APIs retrieve your screen resolution, color depth, and display settings via the window.screen object. This data varies depending on your hardware and personal settings.
The list of installed fonts is the most discriminating attribute. This information depends on your operating system and the software you have installed. Flash plugins easily reveal these fonts.
The canvas fingerprint generates a unique image based on your hardware and drivers. The Electronic Frontier Foundation tests your uniqueness using these techniques.
Atypical operating systems such as FreeBSD make you immediately identifiable. Emojis vary depending on the manufacturer and reveal specific information about your device.
Smartphones offer less diversity of attributes because they lack plugins. However, mobile tracking techniques remain highly effective.
Advertisers use fingerprinting to circumvent users’ cookie blocking. This technique allows them to continue tracking internet users even when they refuse traditional cookies. Companies such as BlueCava, AddThis, and Revenviews use this method to enhance their advertising tracking.
Programmatic advertising leverages this technique to create persistent user profiles. This allows advertisers to track internet users across multiple devices and websites. This cross-device approach gives them a complete view of the user journey without relying on cookies.
Fingerprinting allows advertisers to measure audience size and collect analytics without explicit consent. Unlike cookies, this technique does not require user acceptance. Scripts automatically collect technical information during each visit.
Companies use this method to combat ad fraud and detect bots. The unique fingerprint helps identify fake clicks and artificial interactions. This application helps protect advertisers’ advertising budgets.
Content personalization based on fingerprinting is another major commercial use. Websites adapt their content according to the technical characteristics detected. This study on the effectiveness of Apple’s App Tracking Transparency shows how companies are circumventing the new tracking restrictions.
Google updated its privacy policy in 2015 to mention the use of “similar technologies” to cookies. This vague wording masks the use of fingerprinting by web giants.
Protecting privacy against fingerprinting requires a multi-layered approach combining browser configuration and specialized tools.
Firefox offers the best native protection against fingerprinting. The browser blocks fingerprinting scripts by default in its private browsing modes. Safari and Edge also include limited protection, unlike Chrome, which remains more permissive.
Disable JavaScript on non-essential websites to reduce the amount of information exposed. Flash plugins and other extensions increase your unique digital footprint. Limit their number to the bare minimum.
The Privacy Badger, uBlock Origin, and Ghostery extensions block many known fingerprinting scripts. However, these tools do not detect new techniques. Canvas Blocker specifically prevents visual fingerprinting via the Canvas API.
A VPN changes your IP address but does not mask your browser’s fingerprint. The Tor browser remains the most effective solution by standardizing user fingerprints. It disables JavaScript by default and randomizes certain settings.
Change browsers regularly and clear your browsing data frequently. Use virtual machines for sensitive activities. Avoid non-essential extensions that reveal information about your operating system.
Complete protection against fingerprinting remains complex because modifying your fingerprint can paradoxically make you more identifiable.
Fingerprinting poses a complex threat to digital privacy. Users must now combine several protection strategies: configure secure browsers, use anti-tracking extensions, and stay informed about new online tracking techniques.
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