How To Prevent Canvas From Tracking

As we make our way through the digital era, our privacy remains a significant issue. One potentially unforeseen location for privacy infringement is on the HTML5 canvas. Websites have the ability to utilize JavaScript’s Canvas API to monitor your web activity without your awareness or permission. This blog will provide instructions on how to prevent canvas tracking.

What is HTML5 Canvas?

The HTML5 canvas is an HTML element used to draw graphics on a web page. It uses JavaScript to render graphics and make them interactive. The canvas has several uses, including building graphs, creating animations, or even developing browser games. However, some sites use it for browser fingerprinting, a somewhat controversial tracking technique.

How does canvas fingerprinting work?

Canvas fingerprinting works by exploiting the slight differences in rendering text or 3D graphics on the HTML5 canvas. These variations occur due to different factors such as the browser version, operating system, graphics card, or installed fonts. When your browser renders the image, the site can retrieve that image data – this unique combination of elements forms a unique identifier or a ‘fingerprint’ that can track your browsing activity.

How can we prevent canvas fingerprinting?

1. Using Browser Add-ons:

There are several browser add-ons available that help prevent canvas fingerprinting. One such popular extension is Canvas Defender for Firefox and Chrome. When installed and enabled, this add-on adds random noise to the Canvas fingerprint, thereby making it difficult to track your browsing behavior.

2. Disable JavaScript:

Disabling JavaScript can prevent canvas fingerprinting as it is the backbone of the tracking mechanism. However, this could impact your browsing experience as many websites rely on JavaScript for functionality.

3. Use privacy-focused browsers:

Privacy-focused browsers like Tor or Brave have built-in mechanisms to prevent canvas fingerprinting. However, be aware that these browsers may slow down your browsing speed.

4. Manually blocking canvas fingerprinting:

If you use Firefox, you can manually block canvas fingerprinting using about:config. Here is how:

1. Open Firefox and type "about:config" into the address bar and press Enter.
2. Click "I accept the risk!" to bypass the safety warning.
3. In the search bar, type "privacy.resistFingerprinting".
4. When it appears in the list, double-click on it to change its value to true.

This will enable Firefox’s built-in anti-fingerprinting feature, reducing the efficacy of canvas fingerprinting.


In conclusion, while canvas fingerprinting is a sophisticated tracking technique, there are ways to safeguard your privacy. Whether you choose to use browser add-ons, disable JavaScript, use a privacy-focused browser, or manually block the tracking, the power is in your hands. Be informed and browse safely!