Another thing to bear in mind is that you can often get a long way with core modules that almost do what you want.

For example, you were using Unicode::Escape because it promised to conveniently turn non-ASCII characters into Javascript escape sequences. And this made sense, because that's what you wanted to end up with. Did you look at the core Encode module, though? There's at least one way to use that to solve your problem, and in my tests -- using your test cases -- it comes out about 35% faster than your hand-rolled version, while also providing all the extra stuff Unicode::Escape does like handling non-UTF-8 encodings or invalid UTF-8.

<Reveal this spoiler or all in this thread>

In reply to Re: Faster utf8 escaping. by Porculus
in thread Faster utf8 escaping. by kyle

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