How to stop extensions/add ons like grammarly on contenteditable editors

Question

We are making contenteditable editor. Wondering how to stop extensions like grammarly (if enabled) on editor page using javascript as these extensions insert their own html

Answer 1

So for Grammarly in particular, if you are patient/persistent you can submit a ticket and they will disable their plugin on your site. They won't fix the actual problem, they still inject almost 4MB of extra payload into your editor, I still see the problem when using their plugin on our Dev and QA sites.

I took the approach of Detecting / Alerting Users / Disabling the page. The message was slightly different for Firefox but to keep the sample below brief I stripped out the FF variables and the logging of the offending user.

/* vars intentionally over complicated to make detection more difficult */
//Chrome Message: gc;
var r = /\{0\}/g;
var gc = "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";
var s = "";

MutationObserver = window.MutationObserver || window.WebKitMutationObserver;

var observer = new MutationObserver(function (mutations, observer) {
    for (mutation in mutations) {
    /*console.log(mutations[mutation].target.outerHTML);*/
    var m = mutations[mutation].target.hasAttribute("data-gramm_id");
    if (m) {
        s = window.atob(gc).replace(r, "Grammarly");

        var newDoc = document.open("text/html", "replace");
        newDoc.write(s);
        newDoc.close();
    }
}
});
observer.observe(document, {
    subtree: true,
    attributes: true
});