Except in Safari, whose maxlength implementation seems to treat all emoji as length 1. This means that the maxlength attribute is not fully interoperable between browsers.

I filed a WebKit bug: https://bugs.webkit.org/show_bug.cgi?id=252900

@jkt @simevidas

Following up with that, as I was thinking of some examples of what I mean...

Take kanji, for example. 漢字 is 2 characters, but it's 6 bytes, so is the length 2 or 6?

Or the phrase "Góða nótt" in Icelandic. It's 9 characters (counting the space in the middle), but it's 12 bytes. So, should this fail the maxlength check, if the maxlength is 10?

@ramsey @jkt @simevidas yes, but working on bytes means that the encoding has to be carried thorough the different layers and might cut utf-8 sequences apart (assuming utf-8 being the default encoding)

With either codepoints or grapheme clusters you at least get some valid (while not always sensible) result.