Why does anyone use an encoding other than UTF-8? [closed]

Answer 1

One legitimate reason is when you need to deal with legacy documents, software or hardware that are not Unicode compatible.

Another legitimate reason is that you need to use a programming language / libraries that do not support UTF8 / Unicode well ... or at all.

Other answers mention that UTF-16 is more compact than UTF-8 for Asian languages / characters.

And of course there are reasons like short-sightedness, ignorance, laziness ... and deadlines.

Answer 2

Sometimes they are restricted due to historical/unsupported reasons (I'm developing on Windows using Zend Studio on a Samba share on a Linux box: and something in that mix means I keep reverting to Cp1512 instead of UTF8).

Sometimes you don't need to use UTF-8 (for example when storing a md5 hash in a database: you only need the hexadecimal range 0-9 A-F: why make it a UTF-8 field, which will take at least a byte extra storage instead of normal ASCII).

Sometimes it's just laziness learning the UTF-8 functions for a particular language.

Answer 3

Because you sometimes want to operate easily on codepoints -- then you'd choose f.e. UCS-2 or UCS-4.

Answer 4

http://www.personal.psu.edu/ejp10/blogs/gotunicode/2007/02/cjk-unicode-angst-in-japan-and.html has a good summary + links about the difficulty Japanese users have with Unicode.

http://www.hastingsresearch.com/net/04-unicode-limitations.shtml

Apparently Unicode is moving away from unification due to such complaints.

Answer 5

In UTF-8 code points between 0800 and FFFF take up three bytes in UTF-8 but only two in UTF-16. See the wikipedia comparison for more details, but basically if text heavily uses code points in this range (say, if it's Chinese), UTF-8 files will be larger than UTF-16 files with the same content.