I want to know how toDataURL () converts canvas element into dataURL, and what is done internally here。Recently, we are studying canvas fingerprints. It is said on the Internet that canvas fingerprints are related to devices, operating systems and browsers, but no one can clearly explain what the relationship is, so I would like to ask your opinions on this
Hi @3430606582 and welcome to the community 
According to HTMLCanvasElement.toDataURL() the function returns a base64 encoded image of the current state of the canvas.
Since images also contain meta data that’s probably where some of the information comes from. Additionally, I guess there are small differences on how elements are rendered on different devices/browser.
I recommend reading the original research paper from 2014 that is referenced on Wikipedia. It will probably answer a lot of questions. I will certainly read it 
. Definitively an interesting topic I haven’t heard of until now. Thanks for bringing it up. 
Have a nice day,
Michael