Mapping each base64 char to one word seems rather inefficient. If you have a longer list of N swears (say 256 because it's the size of a byte, making encoding easier), you could produce a more efficient base-N encoding, e.g.:

  var bytes = atob(base64msg),
      swearsMsg = '';
  for (var i = 0; i < bytes.length; i++) {
      newMsg += swears[bytes[i].charAt(0)] + ' ';
  }

Of course, it's still less efficient than base64, but it's an improvement. :)

Yep, that would be a little better.

I suppose you can't get much better than that unless you can come up with hundreds or thousands more swears.

Well, for some X there's always a base-2^X encoding you could use. If you can find 512 swears, you could do base-512. You don't actually have to do a base-2^X encoding, but that's more convenient as it means you're encoding X bits with each "digit".

But yeah, I'm not sure there are that many recognisable swear words in English. Unless you count massive compounds, but now all your words are really long, so you haven't gained anything.

yes, originally I was thinking 256. Unfortunately it's difficult to reach 256 without adding hate/vitrol/racist language

Ah, I see the problem. An awful lot of profanities are ethnic/racial/other minority slurs.

Perhaps some foreign-language and more obscure (dialectal?) English swear words could be used? With crowd-sourcing I'm sure we could reach 256.

as it was, I needed to make a call for swears and look up some different dictionaries to fill up this project

People are somewhat reluctant to share their profanity on GitHub

Make that call here and now on Hacker News, while this still has attention and is on the front page, and I'm sure you'll get contributions!

I suggest putting at the top-level of this comments section, so it gets more attention.

add filler words and turn them into sentences?