If you use that snippet, you should also make sure the HTML and/or the HTTP headers signal the right encoding (i.e. UTF-8)

The only thing "use utf8;" does is remove the need to "decode_utf8" on your string literals*. The binmode(STOUD,":utf8"); signals that all output on STDOUT should be utf-8 encoded.

* i.e. it does nothing to input read from files etc - it only influences literals.