iconv() - UTF-8 to ISO-8859-1 fails with german Umlauts

Question

I want to convert a string from utf-8 to iso-8859-1 in php. (actually I want to remove all characters that are not in the ISO-8859-1 character set).

$text = "test ‍♂️ test xäöüx x@x x€x";

$text = iconv('UTF-8', 'ISO-8859-1//IGNORE', $text);

the expected output would be: test test xäöüx x@x xx

but I get: test test x��x x@x xx

why does iconv have problems with german umlauts? and why are they not removed when in doubt but turned into question marks?

iconv('ISO-8859-1', 'UTF-8', $text): **"test test xäöüx x@x xx** — fx123, Apr 30 '23 at 00:01
I mean yeah... that's the right output. but I don't understand why? iso-8859-1 should contain the umlauts — fx123, Apr 30 '23 at 00:05
It does. You have to tell the browser that the data is in `ISO-8859-1` though. — tkausl, Apr 30 '23 at 00:15

score 2 · Accepted Answer · answered Apr 30 '23 at 09:56

Characters äöü (U+00E4, U+00F6 and U+00FC for what it's worth) have this encoding in ISO-8859-1:

ä: E4
ö: F6
ü: FC

If we run a variation of your code with some additional debugging information:

$text = 'äöü';
$text = iconv('UTF-8', 'ISO-8859-1//IGNORE', $text);
echo bin2hex($text);

... we get the expected output:

e4f6fc

You can see � for a few reasons, all of them related to whatever rendering tool you are using (a web browser, I presume):

ISO-8859-1 not expected or supported.
Missing or incorrect encoding information.
Missing glyph in selected font (this is rare in browsers, since they use fallback fonts).

iconv() - UTF-8 to ISO-8859-1 fails with german Umlauts

1 Answers1