Once a canvas is "tainted," it is no longer considered "origin-clean," and the browser blocks functions that allow you to read its pixel data:
: Attempting to use getImageData() will throw a SecurityError . Tainted Canvas
: The content remains visible to the user, but it cannot be programmatically read back or saved by scripts. Why It Exists Once a canvas is "tainted," it is no
: You cannot use toDataURL() , toBlob() , or captureStream() . This feature protects user privacy by preventing malicious
This feature protects user privacy by preventing malicious websites from "stealing" sensitive images (like bank statements or private photos) that might be cached or authenticated in a user's browser. Without this, a script could draw a private image to a canvas, read its pixels, and send that data to a third-party server. How to Fix It (CORS) cookies - Why is a "tainted canvas" a risk?
A is a security feature in web browsers that prevents the unauthorized extraction of image data from a canvas element . It occurs automatically when an image or video from a different domain (origin) is drawn onto a without proper authorization. Key Effects of Tainting
Once a canvas is "tainted," it is no longer considered "origin-clean," and the browser blocks functions that allow you to read its pixel data:
: Attempting to use getImageData() will throw a SecurityError .
: The content remains visible to the user, but it cannot be programmatically read back or saved by scripts. Why It Exists
: You cannot use toDataURL() , toBlob() , or captureStream() .
This feature protects user privacy by preventing malicious websites from "stealing" sensitive images (like bank statements or private photos) that might be cached or authenticated in a user's browser. Without this, a script could draw a private image to a canvas, read its pixels, and send that data to a third-party server. How to Fix It (CORS) cookies - Why is a "tainted canvas" a risk?
A is a security feature in web browsers that prevents the unauthorized extraction of image data from a canvas element . It occurs automatically when an image or video from a different domain (origin) is drawn onto a without proper authorization. Key Effects of Tainting