JSFiddle - React, Tailwind, and code Playground

JavaScript

var torrent = "magnet:?xt=urn:sha1:YNCKHTQCWBTRNJIV4WNAE52SJUQCZO5C";

if (torrent.match(/magnet:\?xt=urn:[a-z0-9]+:[a-z0-9]{32}/i) !== null) {
    document.write("It's bloody valid!");
}