All HTML Tags supported by a Browser

Question

Using JavaScript, is it possible to obtain a list of the tags that a browser supports?

Answer 1

If you're willing to start with a known list of candidate tags, you could try something like this:

document.createElement("asdf") instanceof HTMLUnknownElement
true
document.createElement("canvas") instanceof HTMLUnknownElement
false

If you need to support IE8, you could use this approach:

function browserSupports(elementTagName) {
    var el = document.createElement(elementTagName);
    return !((el instanceOf HTMLUnknownElement) || (el instanceof HTMLGenericElement));
}

Here's another approach that doesn't rely on specific named constructors.

function browserSupports(elementTagName) {
    var unknownel = document.createElement("zzxcv");
    var el = document.createElement(elementTagName);
    return unknownel.constructor !== el.constructor;
}

It still doesn't seem to work in IE8 though.