Evaluate the condition server-side and don't transmit the HTML in the first place.

Is that faster though? Can your Ruby/PHP/Python running on the server really do the conditional rendering faster than the JavaScript running in the browser?

Your server is already running a scripting language. Putting a script tag on the page necessarily means the browser then needs to parse and interpret some JavaScript, which it simply wouldn't otherwise need to do. If we assume the server and the client both execute an if statement at the same speed, yes, it's purely adding overhead to run that on the client (not to mention the potential for the additional cost of transmitting the eliminated code).

Sorry, I thought it was obvious. The overhead is practically zero compared to the amount of html you can comment out.

You can have a cached static html document with really huge (conditional) comments with tiny performance loss. display:none for example still does all kinds of things. Inserting html with js is even worse.

My experience is mostly with PHP, but the answer to your question is almost always yes.

You can use JS to set `display: none` on the relevant HTML elements

The elements then still appear in the DOM and may be affected by DOM manipulation etc.

So do comments: you can get them via `Node.childNodes` (but not via `Element.children` which only returns elements).

How about slapping the outerHTML into a <template> tag?

Disclaimer: I didn't read the article and am just bikeshedding.