[php] How do I remove accents from characters in a PHP string?

I'm attempting to remove accents from characters in PHP string as the first step to making the string usable in a URL.

I'm using the following code:

$input = "Fóø Bår";

setlocale(LC_ALL, "en_US.utf8");
$output = iconv("utf-8", "ascii//TRANSLIT", $input);

print($output);

The output I would expect would be something like this:

F'oo Bar

However, instead of the accented characters being transliterated they are replaced with question marks:

F?? B?r

Everything I can find online indicates that setting the locale will fix this problem, however I'm already doing this. I've already checked the following details:

  1. The locale I am setting is supported by the server (included in the list produced by locale -a)
  2. The source and target encodings (UTF-8 and ASCII) are supported by the server's version of iconv (included in the list produced by iconv -l)
  3. The input string is UTF-8 encoded (verified using PHP's mb_check_encoding function, as suggested in the answer by mercator)
  4. The call to setlocale is successful (it returns 'en_US.utf8' rather than FALSE)

The cause of the problem:

The server is using the wrong implementation of iconv. It has the glibc version instead of the required libiconv version.

Note that the iconv function on some systems may not work as you expect. In such case, it'd be a good idea to install the GNU libiconv library. It will most likely end up with more consistent results.
PHP manual's introduction to iconv

Details about the iconv implementation that is used by PHP are included in the output of the phpinfo function.

(I'm not able to re-compile PHP with the correct iconv library on the server I'm working with for this project so the answer I've accepted below is the one that was most useful for removing accents without iconv support.)

This question is related to php iconv

The answer is


One of the tricks I stumbled upon on the web was using htmlentities then stripping the encoded character :

$stripped = preg_replace('`&[^;]+;`','',htmlentities($string));

Not perfect but it does work well in some case.

But, you're writing about creating an URL string, so urlencode and its counterpart urldecode may be better. Or, if you are creating a query string, use this last function : http_build_query.


if you have http://php.net/manual/en/book.intl.php available, this solved your problem

$string = "Fóø Bår";
$transliterator = Transliterator::createFromRules(':: Any-Latin; :: Latin-ASCII; :: NFD; :: [:Nonspacing Mark:] Remove; :: Lower(); :: NFC;', Transliterator::FORWARD);
echo $normalized = $transliterator->transliterate($string);

I agree with georgebrock's comment.

If you find a way to get //TRANSLIT to work, you can build friendly URLs:

  1. use iconv with //TRANSLIT ñ => n~
    • remove non-alphanumeric non-whitespace chars inside words: $url = preg_replace( '/(\w)[^\w\s](\w)/', '$1$2', $url );
    • replace remaining separations: $url = preg_replace( '/[^a-z0-9]+/', '-', $url );
    • remove double/leading/traling: $url = preg_replace( '-', e.g. '/(?:(^|\-)\-+|\-$)/', '', $url );

If you can't get it to work, replace setp 1 with strtr/character-based replacement, like Xetius' solution.


In laravel you can simply use str_slug($accentedPhrase) and if you care about dash (-) that this method substitute with space you can use str_replace('-', ' ', str_slug($accentedPhrase))


WordPress' implementation is definitly the safest for UTF8 strings. For Latin1 strings, a simple strtr does the job, but ensure you're saving your script in LATIN1 format, not UTF-8.


What's wrong with this one? Works with UTF8

function strip_accents($s){
  return str_replace(
    explode(' ', preg_replace('/ +/', ' ', 'c c ž š d  C C Ž Š Ð  à á â ã ä ç è é ê ë ì í î ï ñ ò ó ô õ ö ù ú û ü ý ÿ À Á Â Ã Ä Ç È É Ê Ë Ì Í Î Ï Ñ Ò Ó Ô Õ Ö Ù Ú Û Ü Ý')),
    explode(' ', preg_replace('/ +/', ' ', 'c c z s dj C C Z S DJ a a a a a c e e e e i i i i n o o o o o u u u u y y A A A A A C E E E E I I I I N O O O O O U U U U Y')),
    $s);
}

It can be faster by not using preg_replace, but speed was not my goal here.


Based on @Mimouni answer I made this function to transliterate Accented strings to Non Accented strings.

/**
 * @param $str Convert string to lowercase and replace special chars to equivalents ou remove its
 * @return string
 */
function _slugify(string $string): string
{
    $str = $string; // for comparisons
    $str = _toUtf8($str); // Force to work with string in UTF-8
    $str = iconv('UTF-8', 'ASCII//TRANSLIT', $str);

    if ($str != htmlentities($string, ENT_QUOTES, 'UTF-8')) { // iconv fails
        $str = _toUtf8($string);
        $str = htmlentities($str, ENT_QUOTES, 'UTF-8');
        $str = preg_replace('#&([a-z]{1,2})(acute|cedil|circ|grave|lig|orn|ring|slash|th|tilde|uml);#i', '$1', $str);
        // Need to strip non ASCII chars or any other than a-z, A-Z, 0-9...
        $str = html_entity_decode($str, ENT_QUOTES, 'UTF-8');
        $str = preg_replace(array('#[^0-9a-z]#i', '#[ -]+#'), ' ', $str);
        $str = trim($str, ' -');
    }

    // lowercase
    $string = strtolower($str);

    return $string;
}

To convert strings to UTF-8, here I use the Multi Byte String extension. Note that I break string in pieces to avoid trouble with mixed content (I have such situation) and convert word by word.

/**
 * @param $str string String in any encoding
 * @return string
 */
function _toUtf8(string $str_in): ?string
{
    if (!function_exists('mb_detect_encoding')) {
        throw new \Exception('The Multi Byte String extension is absent!');
    }
    $str_out = [];
    $words = explode(" ", $str_in);
    foreach ($words as $word) {
        $current_encoding = mb_detect_encoding($word, 'UTF-8, ASCII, ISO-8859-1');
        $str_out[] = mb_convert_encoding($word, 'UTF-8', $current_encoding);
    }
    return implode(" ", $str_out);
}

Footer Notes: Was the only solution that pass in PHPUnit UnitTests in Windows command Line (locale issues) The @gabo solution should work but unfortunately not for me


Indeed is a matter of taste. There are many flavors for converting such letters.

function replaceAccents($str)
{
  $a = array('À', 'Á', 'Â', 'Ã', 'Ä', 'Å', 'Æ', 'Ç', 'È', 'É', 'Ê', 'Ë', 'Ì', 'Í', 'Î', 'Ï', 'Ð', 'Ñ', 'Ò', 'Ó', 'Ô', 'Õ', 'Ö', 'Ø', 'Ù', 'Ú', 'Û', 'Ü', 'Ý', 'ß', 'à', 'á', 'â', 'ã', 'ä', 'å', 'æ', 'ç', 'è', 'é', 'ê', 'ë', 'ì', 'í', 'î', 'ï', 'ñ', 'ò', 'ó', 'ô', 'õ', 'ö', 'ø', 'ù', 'ú', 'û', 'ü', 'ý', 'ÿ', 'A', 'a', 'A', 'a', 'A', 'a', 'C', 'c', 'C', 'c', 'C', 'c', 'C', 'c', 'D', 'd', 'Ð', 'd', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'G', 'g', 'G', 'g', 'G', 'g', 'G', 'g', 'H', 'h', 'H', 'h', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', '?', '?', 'J', 'j', 'K', 'k', 'L', 'l', 'L', 'l', 'L', 'l', '?', '?', 'L', 'l', 'N', 'n', 'N', 'n', 'N', 'n', '?', 'O', 'o', 'O', 'o', 'O', 'o', 'Œ', 'œ', 'R', 'r', 'R', 'r', 'R', 'r', 'S', 's', 'S', 's', 'S', 's', 'Š', 'š', 'T', 't', 'T', 't', 'T', 't', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'W', 'w', 'Y', 'y', 'Ÿ', 'Z', 'z', 'Z', 'z', 'Ž', 'ž', '?', 'ƒ', 'O', 'o', 'U', 'u', 'A', 'a', 'I', 'i', 'O', 'o', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', '?', '?', '?', '?', '?', '?');
  $b = array('A', 'A', 'A', 'A', 'A', 'A', 'AE', 'C', 'E', 'E', 'E', 'E', 'I', 'I', 'I', 'I', 'D', 'N', 'O', 'O', 'O', 'O', 'O', 'O', 'U', 'U', 'U', 'U', 'Y', 's', 'a', 'a', 'a', 'a', 'a', 'a', 'ae', 'c', 'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i', 'n', 'o', 'o', 'o', 'o', 'o', 'o', 'u', 'u', 'u', 'u', 'y', 'y', 'A', 'a', 'A', 'a', 'A', 'a', 'C', 'c', 'C', 'c', 'C', 'c', 'C', 'c', 'D', 'd', 'D', 'd', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'G', 'g', 'G', 'g', 'G', 'g', 'G', 'g', 'H', 'h', 'H', 'h', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', 'IJ', 'ij', 'J', 'j', 'K', 'k', 'L', 'l', 'L', 'l', 'L', 'l', 'L', 'l', 'l', 'l', 'N', 'n', 'N', 'n', 'N', 'n', 'n', 'O', 'o', 'O', 'o', 'O', 'o', 'OE', 'oe', 'R', 'r', 'R', 'r', 'R', 'r', 'S', 's', 'S', 's', 'S', 's', 'S', 's', 'T', 't', 'T', 't', 'T', 't', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'W', 'w', 'Y', 'y', 'Y', 'Z', 'z', 'Z', 'z', 'Z', 'z', 's', 'f', 'O', 'o', 'U', 'u', 'A', 'a', 'I', 'i', 'O', 'o', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'A', 'a', 'AE', 'ae', 'O', 'o');
  return str_replace($a, $b, $str);
}

The easiest way is to use iconv() PHP native function.

 echo iconv('UTF-8', 'ASCII//TRANSLIT//IGNORE', "Thîs îs à vêry wrong séntènce!");

 // output: This is a very wrong sentence!

<?php
/* 
 * Thanks:
 *   - The idea of extracting accents equiv chars with the help of the HTMLSpecialChars convertion was taking from ICanBoogie Package of 'Olivier Laviale' {@link http://www.weirdog.com/blog/php/supprimer-les-accents-des-caracteres-accentues.html}
*/
function accentCharsModifier($str){
    if(($length=mb_strlen($str,"UTF-8"))<strlen($str)){
        $i=$count=0;
        while($i<$length){
            if(strlen($c=mb_substr($str,$i,1,"UTF-8"))>1){
                $he=htmlentities($c); 
                if(($nC=preg_replace("#&([A-Za-z])(?:acute|cedil|caron|circ|grave|orn|ring|slash|th|tilde|uml);#", "\\1", $he))!=$he ||
                    ($nC=preg_replace("#&([A-Za-z]{2})(?:lig);#", "\\1", $he))!=$he ||
                    ($nC=preg_replace("#&[^;]+;#", "", $he))!=$he){
                    $str=str_replace($c,$nC,$str,$count);if($nC==""){$length=$length-$count;$i--;}
                }
            }
            $i++;
        }
    }
    return $str;
}
echo accentCharsModifier("&éôpkAÈû");
?>

UTF-8 friendly version of the simple function posted above by Gino:

function stripAccents($str) {
    return strtr(utf8_decode($str), utf8_decode('àáâãäçèéêëìíîïñòóôõöùúûüýÿÀÁÂÃÄÇÈÉÊËÌÍÎÏÑÒÓÔÕÖÙÚÛÜÝ'), 'aaaaaceeeeiiiinooooouuuuyyAAAAACEEEEIIIINOOOOOUUUUY');
}

Had to come to this because my php document was UTF-8 encoded.

Hope it helps.


What about the WordPress implementation?

function remove_accents($string) {
    if ( !preg_match('/[\x80-\xff]/', $string) )
        return $string;

    $chars = array(
    // Decompositions for Latin-1 Supplement
    chr(195).chr(128) => 'A', chr(195).chr(129) => 'A',
    chr(195).chr(130) => 'A', chr(195).chr(131) => 'A',
    chr(195).chr(132) => 'A', chr(195).chr(133) => 'A',
    chr(195).chr(135) => 'C', chr(195).chr(136) => 'E',
    chr(195).chr(137) => 'E', chr(195).chr(138) => 'E',
    chr(195).chr(139) => 'E', chr(195).chr(140) => 'I',
    chr(195).chr(141) => 'I', chr(195).chr(142) => 'I',
    chr(195).chr(143) => 'I', chr(195).chr(145) => 'N',
    chr(195).chr(146) => 'O', chr(195).chr(147) => 'O',
    chr(195).chr(148) => 'O', chr(195).chr(149) => 'O',
    chr(195).chr(150) => 'O', chr(195).chr(153) => 'U',
    chr(195).chr(154) => 'U', chr(195).chr(155) => 'U',
    chr(195).chr(156) => 'U', chr(195).chr(157) => 'Y',
    chr(195).chr(159) => 's', chr(195).chr(160) => 'a',
    chr(195).chr(161) => 'a', chr(195).chr(162) => 'a',
    chr(195).chr(163) => 'a', chr(195).chr(164) => 'a',
    chr(195).chr(165) => 'a', chr(195).chr(167) => 'c',
    chr(195).chr(168) => 'e', chr(195).chr(169) => 'e',
    chr(195).chr(170) => 'e', chr(195).chr(171) => 'e',
    chr(195).chr(172) => 'i', chr(195).chr(173) => 'i',
    chr(195).chr(174) => 'i', chr(195).chr(175) => 'i',
    chr(195).chr(177) => 'n', chr(195).chr(178) => 'o',
    chr(195).chr(179) => 'o', chr(195).chr(180) => 'o',
    chr(195).chr(181) => 'o', chr(195).chr(182) => 'o',
    chr(195).chr(182) => 'o', chr(195).chr(185) => 'u',
    chr(195).chr(186) => 'u', chr(195).chr(187) => 'u',
    chr(195).chr(188) => 'u', chr(195).chr(189) => 'y',
    chr(195).chr(191) => 'y',
    // Decompositions for Latin Extended-A
    chr(196).chr(128) => 'A', chr(196).chr(129) => 'a',
    chr(196).chr(130) => 'A', chr(196).chr(131) => 'a',
    chr(196).chr(132) => 'A', chr(196).chr(133) => 'a',
    chr(196).chr(134) => 'C', chr(196).chr(135) => 'c',
    chr(196).chr(136) => 'C', chr(196).chr(137) => 'c',
    chr(196).chr(138) => 'C', chr(196).chr(139) => 'c',
    chr(196).chr(140) => 'C', chr(196).chr(141) => 'c',
    chr(196).chr(142) => 'D', chr(196).chr(143) => 'd',
    chr(196).chr(144) => 'D', chr(196).chr(145) => 'd',
    chr(196).chr(146) => 'E', chr(196).chr(147) => 'e',
    chr(196).chr(148) => 'E', chr(196).chr(149) => 'e',
    chr(196).chr(150) => 'E', chr(196).chr(151) => 'e',
    chr(196).chr(152) => 'E', chr(196).chr(153) => 'e',
    chr(196).chr(154) => 'E', chr(196).chr(155) => 'e',
    chr(196).chr(156) => 'G', chr(196).chr(157) => 'g',
    chr(196).chr(158) => 'G', chr(196).chr(159) => 'g',
    chr(196).chr(160) => 'G', chr(196).chr(161) => 'g',
    chr(196).chr(162) => 'G', chr(196).chr(163) => 'g',
    chr(196).chr(164) => 'H', chr(196).chr(165) => 'h',
    chr(196).chr(166) => 'H', chr(196).chr(167) => 'h',
    chr(196).chr(168) => 'I', chr(196).chr(169) => 'i',
    chr(196).chr(170) => 'I', chr(196).chr(171) => 'i',
    chr(196).chr(172) => 'I', chr(196).chr(173) => 'i',
    chr(196).chr(174) => 'I', chr(196).chr(175) => 'i',
    chr(196).chr(176) => 'I', chr(196).chr(177) => 'i',
    chr(196).chr(178) => 'IJ',chr(196).chr(179) => 'ij',
    chr(196).chr(180) => 'J', chr(196).chr(181) => 'j',
    chr(196).chr(182) => 'K', chr(196).chr(183) => 'k',
    chr(196).chr(184) => 'k', chr(196).chr(185) => 'L',
    chr(196).chr(186) => 'l', chr(196).chr(187) => 'L',
    chr(196).chr(188) => 'l', chr(196).chr(189) => 'L',
    chr(196).chr(190) => 'l', chr(196).chr(191) => 'L',
    chr(197).chr(128) => 'l', chr(197).chr(129) => 'L',
    chr(197).chr(130) => 'l', chr(197).chr(131) => 'N',
    chr(197).chr(132) => 'n', chr(197).chr(133) => 'N',
    chr(197).chr(134) => 'n', chr(197).chr(135) => 'N',
    chr(197).chr(136) => 'n', chr(197).chr(137) => 'N',
    chr(197).chr(138) => 'n', chr(197).chr(139) => 'N',
    chr(197).chr(140) => 'O', chr(197).chr(141) => 'o',
    chr(197).chr(142) => 'O', chr(197).chr(143) => 'o',
    chr(197).chr(144) => 'O', chr(197).chr(145) => 'o',
    chr(197).chr(146) => 'OE',chr(197).chr(147) => 'oe',
    chr(197).chr(148) => 'R',chr(197).chr(149) => 'r',
    chr(197).chr(150) => 'R',chr(197).chr(151) => 'r',
    chr(197).chr(152) => 'R',chr(197).chr(153) => 'r',
    chr(197).chr(154) => 'S',chr(197).chr(155) => 's',
    chr(197).chr(156) => 'S',chr(197).chr(157) => 's',
    chr(197).chr(158) => 'S',chr(197).chr(159) => 's',
    chr(197).chr(160) => 'S', chr(197).chr(161) => 's',
    chr(197).chr(162) => 'T', chr(197).chr(163) => 't',
    chr(197).chr(164) => 'T', chr(197).chr(165) => 't',
    chr(197).chr(166) => 'T', chr(197).chr(167) => 't',
    chr(197).chr(168) => 'U', chr(197).chr(169) => 'u',
    chr(197).chr(170) => 'U', chr(197).chr(171) => 'u',
    chr(197).chr(172) => 'U', chr(197).chr(173) => 'u',
    chr(197).chr(174) => 'U', chr(197).chr(175) => 'u',
    chr(197).chr(176) => 'U', chr(197).chr(177) => 'u',
    chr(197).chr(178) => 'U', chr(197).chr(179) => 'u',
    chr(197).chr(180) => 'W', chr(197).chr(181) => 'w',
    chr(197).chr(182) => 'Y', chr(197).chr(183) => 'y',
    chr(197).chr(184) => 'Y', chr(197).chr(185) => 'Z',
    chr(197).chr(186) => 'z', chr(197).chr(187) => 'Z',
    chr(197).chr(188) => 'z', chr(197).chr(189) => 'Z',
    chr(197).chr(190) => 'z', chr(197).chr(191) => 's'
    );

    $string = strtr($string, $chars);

    return $string;
}

To understand what this function does, check the conversion table:

À => A
Á => A
 => A
à => A
Ä => A
Å => A
Ç => C
È => E
É => E
Ê => E
Ë => E
Ì => I
Í => I
Î => I
Ï => I
Ñ => N
Ò => O
Ó => O
Ô => O
Õ => O
Ö => O
Ù => U
Ú => U
Û => U
Ü => U
Ý => Y
ß => s
à => a
á => a
â => a
ã => a
ä => a
å => a
ç => c
è => e
é => e
ê => e
ë => e
ì => i
í => i
î => i
ï => i
ñ => n
ò => o
ó => o
ô => o
õ => o
ö => o
ù => u
ú => u
û => u
ü => u
ý => y
ÿ => y
A => A
a => a
A => A
a => a
A => A
a => a
C => C
c => c
C => C
c => c
C => C
c => c
C => C
c => c
D => D
d => d
Ð => D
d => d
E => E
e => e
E => E
e => e
E => E
e => e
E => E
e => e
E => E
e => e
G => G
g => g
G => G
g => g
G => G
g => g
G => G
g => g
H => H
h => h
H => H
h => h
I => I
i => i
I => I
i => i
I => I
i => i
I => I
i => i
I => I
i => i
? => IJ
? => ij
J => J
j => j
K => K
k => k
? => k
L => L
l => l
L => L
l => l
L => L
l => l
? => L
? => l
L => L
l => l
N => N
n => n
N => N
n => n
N => N
n => n
? => N
? => n
? => N
O => O
o => o
O => O
o => o
O => O
o => o
Π=> OE
œ => oe
R => R
r => r
R => R
r => r
R => R
r => r
S => S
s => s
S => S
s => s
S => S
s => s
Š => S
š => s
T => T
t => t
T => T
t => t
T => T
t => t
U => U
u => u
U => U
u => u
U => U
u => u
U => U
u => u
U => U
u => u
U => U
u => u
W => W
w => w
Y => Y
y => y
Ÿ => Y
Z => Z
z => z
Z => Z
z => z
Ž => Z
ž => z
? => s

You can generate the conversion table yourself by simply iterating over the $chars array of the function:

foreach($chars as $k=>$v) {
   printf("%s -> %s", $k, $v);
}

This answer I've got following tips here, so it is not really mine. It works for me using LATIN1 or UTF-8. If you use other charsets, you probably should add them to mb_detect_encoding function. Correct environment set is probably needed also.

function NoAccents($s){
        return iconv(mb_detect_encoding($s,'UTF-8, ASCII, ISO-8859-1'),'ASCII//TRANSLIT//INGORE',$s);
}

I just created a removeAccents method based on the reading of this thread and this other one too (How to remove accents and turn letters into "plain" ASCII characters?).

The method is here: https://github.com/lingtalfi/Bat/blob/master/StringTool.md#removeaccents

Tests are here: https://github.com/lingtalfi/Bat/blob/master/btests/StringTool/removeAccents/stringTool.removeAccents.test.php,

and here is what was tested so far:

$a = [
    // easy
    '',
    'a',
    'après',
    'dédé fait la fête ?',
    // hard
    'àáâãäçèéêëìíîïñòóôõöùúûüýÿÀÁÂÃÄÇÈÉÊËÌÍÎÏÑÒÓÔÕÖÙÚÛÜÝ',
    'ZZCNASLEÓzzcnasleó',
    'qqqqZZCNASLEÓzzcnasleóqqq',
    'ŠŽšžŸÀÁÂÃÄÅÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝàáâãäåçèéêëìíîïðñòóôõöøùúûüýÿ',       
    'ÀÁÂÃÄÅÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝàáâãäåçèéêëìíîïñòóôõöøùúûüýÿ',
    'AaAaAaCcCcCcCcDdÐdEeEeEeEeEeGgGgGgGgHhHhIiIiIiIiIJjKk',
    'LlLlLl??LlNnNnNn?OoOoOoRrRrRrSsSsSsŠšTtTtTtUuUuUuUuUuUuWwYyŸZzZzŽž',
    '?ƒOoUuAaIiOoUuUuUuUuUu????',
    '??',
];

and it converts only accentuated things (letters/ligatures/cédilles/some letters with a line through/...?).

Here is the content of the method: (https://github.com/lingtalfi/Bat/blob/master/StringTool.php#L83)

public static function removeAccents($str)
{
    static $map = [
        // single letters
        'à' => 'a',
        'á' => 'a',
        'â' => 'a',
        'ã' => 'a',
        'ä' => 'a',
        'a' => 'a',
        'å' => 'a',
        'a' => 'a',
        'a' => 'a',
        'a' => 'a',
        '?' => 'a',
        'À' => 'A',
        'Á' => 'A',
        'Â' => 'A',
        'Ã' => 'A',
        'Ä' => 'A',
        'A' => 'A',
        'Å' => 'A',
        'A' => 'A',
        'A' => 'A',
        'A' => 'A',
        '?' => 'A',


        'ç' => 'c',
        'c' => 'c',
        'c' => 'c',
        'c' => 'c',
        'c' => 'c',
        'Ç' => 'C',
        'C' => 'C',
        'C' => 'C',
        'C' => 'C',
        'C' => 'C',

        'd' => 'd',
        'd' => 'd',
        'Ð' => 'D',
        'D' => 'D',
        'Ð' => 'D',


        'è' => 'e',
        'é' => 'e',
        'ê' => 'e',
        'ë' => 'e',
        'e' => 'e',
        'e' => 'e',
        'e' => 'e',
        'e' => 'e',
        'e' => 'e',
        'È' => 'E',
        'É' => 'E',
        'Ê' => 'E',
        'Ë' => 'E',
        'E' => 'E',
        'E' => 'E',
        'E' => 'E',
        'E' => 'E',
        'E' => 'E',

        'ƒ' => 'f',


        'g' => 'g',
        'g' => 'g',
        'g' => 'g',
        'g' => 'g',
        'G' => 'G',
        'G' => 'G',
        'G' => 'G',
        'G' => 'G',


        'h' => 'h',
        'h' => 'h',
        'H' => 'H',
        'H' => 'H',

        'ì' => 'i',
        'í' => 'i',
        'î' => 'i',
        'ï' => 'i',
        'i' => 'i',
        'i' => 'i',
        'i' => 'i',
        'i' => 'i',
        '?' => 'i',
        'i' => 'i',
        'Ì' => 'I',
        'Í' => 'I',
        'Î' => 'I',
        'Ï' => 'I',
        'I' => 'I',
        'I' => 'I',
        'I' => 'I',
        'I' => 'I',
        'I' => 'I',
        'I' => 'I',

        'j' => 'j',
        'J' => 'J',

        'k' => 'k',
        'K' => 'K',


        'l' => 'l',
        'l' => 'l',
        'l' => 'l',
        'l' => 'l',
        '?' => 'l',
        'L' => 'L',
        'L' => 'L',
        'L' => 'L',
        'L' => 'L',
        '?' => 'L',


        'ñ' => 'n',
        'n' => 'n',
        'n' => 'n',
        'n' => 'n',
        '?' => 'n',
        'Ñ' => 'N',
        'N' => 'N',
        'N' => 'N',
        'N' => 'N',

        'ò' => 'o',
        'ó' => 'o',
        'ô' => 'o',
        'õ' => 'o',
        'ö' => 'o',
        'ð' => 'o',
        'ø' => 'o',
        'o' => 'o',
        'o' => 'o',
        'o' => 'o',
        'o' => 'o',
        'o' => 'o',
        '?' => 'o',
        'Ò' => 'O',
        'Ó' => 'O',
        'Ô' => 'O',
        'Õ' => 'O',
        'Ö' => 'O',
        'Ø' => 'O',
        'O' => 'O',
        'O' => 'O',
        'O' => 'O',
        'O' => 'O',
        'O' => 'O',
        '?' => 'O',


        'r' => 'r',
        'r' => 'r',
        'r' => 'r',
        'R' => 'R',
        'R' => 'R',
        'R' => 'R',


        's' => 's',
        'š' => 's',
        's' => 's',
        's' => 's',
        'S' => 'S',
        'Š' => 'S',
        'S' => 'S',
        'S' => 'S',

        't' => 't',
        't' => 't',
        't' => 't',
        'T' => 'T',
        'T' => 'T',
        'T' => 'T',


        'ù' => 'u',
        'ú' => 'u',
        'û' => 'u',
        'ü' => 'u',
        'u' => 'u',
        'u' => 'u',
        'u' => 'u',
        'u' => 'u',
        'u' => 'u',
        'u' => 'u',
        'u' => 'u',
        'u' => 'u',
        'u' => 'u',
        'u' => 'u',
        'u' => 'u',
        'u' => 'u',
        'Ù' => 'U',
        'Ú' => 'U',
        'Û' => 'U',
        'Ü' => 'U',
        'U' => 'U',
        'U' => 'U',
        'U' => 'U',
        'U' => 'U',
        'U' => 'U',
        'U' => 'U',
        'U' => 'U',
        'U' => 'U',
        'U' => 'U',
        'U' => 'U',
        'U' => 'U',
        'U' => 'U',


        'w' => 'w',
        'W' => 'W',

        'ý' => 'y',
        'ÿ' => 'y',
        'y' => 'y',
        'Ý' => 'Y',
        'Ÿ' => 'Y',
        'Y' => 'Y',

        'z' => 'z',
        'z' => 'z',
        'ž' => 'z',
        'Z' => 'Z',
        'Z' => 'Z',
        'Ž' => 'Z',


        // accentuated ligatures
        '?' => 'A',
        '?' => 'a',
    ];
    return strtr($str, $map);
}

If the main task is just to use the string in a URL, why not to use slugyfier?

composer require cocur/slugify

then

use Cocur\Slugify\Slugify;

$slugify = new Slugify();
echo $slugify->slugify('Fóø Bår');

It also has many bridges for popular frameworks. E.g. you can use Doctrine Extensions Sluggable behaviour to generate automatically unique slug for each entity in DB and use it in URL.

If you want just to wipe out all accents you can play around with rulesets to satisfy the requirements.


$unwanted_array = array(    '&amp;' => 'and', '&' => 'and', '@' => 'at', '©' => 'c', '®' => 'r', 
'°'=>'','¸'=>'','?'=>'','¯'=>'','_'=>'',
'Á'=>'a','á'=>'a','À'=>'a','à'=>'a','A'=>'a','a'=>'a','?'=>'a','?'=>'A','?'=>'A',
'?'=>'a','?'=>'a','?'=>'A','?'=>'a','?'=>'A','Â'=>'a','â'=>'a','?'=>'a','?'=>'A',
'?'=>'a','?'=>'a','?'=>'a','?'=>'A','A'=>'a','a'=>'a','Å'=>'a','å'=>'a','?'=>'a',
'?'=>'a','Ä'=>'a','ä'=>'a','ã'=>'a','Ã'=>'A','A'=>'a','a'=>'a','A'=>'a','a'=>'a',
'?'=>'a','?'=>'a','?'=>'A','?'=>'a','?'=>'a','?'=>'A','?'=>'a','?'=>'A','Æ'=>'ae',
'æ'=>'ae','?'=>'ae','?'=>'ae','?'=>'a','?'=>'A',
'C'=>'c','c'=>'c','C'=>'c','c'=>'c','C'=>'c','c'=>'c','C'=>'c','c'=>'c','Ç'=>'c','ç'=>'c',
'D'=>'d','d'=>'d','?'=>'D','?'=>'d','Ð'=>'d','d'=>'d','?'=>'D','?'=>'d','?'=>'D','?'=>'d','ð'=>'d','Ð'=>'D',
'É'=>'e','é'=>'e','È'=>'e','è'=>'e','E'=>'e','e'=>'e','ê'=>'e','?'=>'e','?'=>'E','?'=>'e',
'?'=>'E','E'=>'e','e'=>'e','Ë'=>'e','ë'=>'e','E'=>'e','e'=>'e','E'=>'e','e'=>'e','E'=>'e',
'e'=>'e','?'=>'e','?'=>'E','?'=>'e','?'=>'e','?'=>'e','?'=>'E','?'=>'e',
'?'=>'E','?'=>'e','?'=>'E','?'=>'e','?'=>'E','?'=>'e','?'=>'E',
'ƒ'=>'f',
'G'=>'g','g'=>'g','G'=>'g','g'=>'g','G'=>'G','g'=>'g','G'=>'g','g'=>'g','G'=>'g','g'=>'g',
'H_'=>'H','h_'=>'h','H'=>'h','h'=>'h','?'=>'H','?'=>'h','?'=>'H','?'=>'h','H'=>'h','h'=>'h','?'=>'H','?'=>'h',
'?'=>'I','Í'=>'i','í'=>'i','Ì'=>'i','ì'=>'i','I'=>'i','i'=>'i','Î'=>'i','î'=>'i','I'=>'i','i'=>'i',
'Ï'=>'i','ï'=>'i','?'=>'I','?'=>'i','I'=>'i','i'=>'i','I'=>'i','I'=>'i','i'=>'i','I'=>'i','i'=>'i',
'?'=>'I','?'=>'I','?'=>'i','?'=>'ij','?'=>'ij','i'=>'i',
'J'=>'j','j'=>'j',
'K'=>'k','k'=>'k','?'=>'K','?'=>'k',
'L'=>'l','l'=>'l','L'=>'l','l'=>'l','L'=>'l','l'=>'l','L'=>'l','l'=>'l','?'=>'l','?'=>'l',
'N'=>'n','n'=>'n','N'=>'n','n'=>'n','Ñ'=>'N','ñ'=>'n','N'=>'n','n'=>'n','?'=>'N','?'=>'n','?'=>'n','?'=>'n',
'Ó'=>'o','ó'=>'o','Ò'=>'o','ò'=>'o','O'=>'o','o'=>'o','Ô'=>'o','ô'=>'o','?'=>'o','?'=>'O','?'=>'o',
'?'=>'O','?'=>'o','?'=>'O','O'=>'o','o'=>'o','Ö'=>'o','ö'=>'o','O'=>'o','o'=>'o','Õ'=>'o','õ'=>'o',
'Ø'=>'o','ø'=>'o','?'=>'o','?'=>'o','O'=>'O','o'=>'o','O'=>'O','o'=>'o','O'=>'o','o'=>'o','?'=>'o',
'?'=>'O','O'=>'o','o'=>'o','?'=>'o','?'=>'O','?'=>'o','?'=>'O','?'=>'o','?'=>'O','?'=>'o','?'=>'O',
'?'=>'o','?'=>'O','?'=>'o','?'=>'O','?'=>'o','?'=>'O','?'=>'o','?'=>'O','?'=>'o','?'=>'O',
'Œ'=>'oe','œ'=>'oe',
'?'=>'k',
'R'=>'r','r'=>'r','R'=>'r','r'=>'r','?'=>'r','R'=>'r','r'=>'r','?'=>'R','?'=>'r','?'=>'R','?'=>'r',
'S_'=>'S','s_'=>'s','S'=>'s','s'=>'s','S'=>'s','s'=>'s','Š'=>'s','š'=>'s','S'=>'s','s'=>'s',
'?'=>'S','?'=>'s','?'=>'S','?'=>'s',
'?'=>'z','ß'=>'ss','T'=>'t','t'=>'t','T'=>'t','t'=>'t','?'=>'T','?'=>'t','?'=>'T',
'?'=>'t','?'=>'T','?'=>'t','™'=>'tm','T'=>'t','t'=>'t',
'Ú'=>'u','ú'=>'u','Ù'=>'u','ù'=>'u','U'=>'u','u'=>'u','Û'=>'u','û'=>'u','U'=>'u','u'=>'u','U'=>'u','u'=>'u',
'Ü'=>'u','ü'=>'u','U'=>'u','u'=>'u','U'=>'u','u'=>'u','U'=>'u','u'=>'u','U'=>'u','u'=>'u','U'=>'u','u'=>'u',
'U'=>'u','u'=>'u','U'=>'u','u'=>'u','U'=>'u','u'=>'u','U'=>'u','u'=>'u','?'=>'u','?'=>'U','?'=>'u','?'=>'U',
'?'=>'u','?'=>'U','?'=>'u','?'=>'U','?'=>'u','?'=>'U','?'=>'u','?'=>'U','?'=>'u','?'=>'U',
'W'=>'w','w'=>'w',
'Ý'=>'y','ý'=>'y','?'=>'y','?'=>'Y','Y'=>'y','y'=>'y','ÿ'=>'y','Ÿ'=>'y','?'=>'y','?'=>'Y','?'=>'y','?'=>'Y',
'Z_'=>'Z','z_'=>'z','Z'=>'z','z'=>'z','Ž'=>'z','ž'=>'z','Z'=>'z','z'=>'z','?'=>'Z','?'=>'z',
'þ'=>'p','?'=>'n','?'=>'a','?'=>'a','?'=>'b','?'=>'b','?'=>'v','?'=>'v','?'=>'g','?'=>'g','?'=>'g','?'=>'g',
'?'=>'d','?'=>'d','?'=>'e','?'=>'e','?'=>'jo','?'=>'jo','?'=>'e','?'=>'e','?'=>'zh','?'=>'zh','?'=>'z','?'=>'z',
'?'=>'i','?'=>'i','?'=>'i','?'=>'i','?'=>'i','?'=>'i','?'=>'j','?'=>'j','?'=>'k','?'=>'k','?'=>'l','?'=>'l',
'?'=>'m','?'=>'m','?'=>'n','?'=>'n','?'=>'o','?'=>'o','?'=>'p','?'=>'p','?'=>'r','?'=>'r','?'=>'s','?'=>'s',
'?'=>'t','?'=>'t','?'=>'u','?'=>'u','?'=>'f','?'=>'f','?'=>'h','?'=>'h','?'=>'c','?'=>'c','?'=>'ch','?'=>'ch',
'?'=>'sh','?'=>'sh','?'=>'sch','?'=>'sch','?'=>'-',
'?'=>'-','?'=>'y','?'=>'y','?'=>'-','?'=>'-',
'?'=>'je','?'=>'je','?'=>'ju','?'=>'ju','?'=>'ja','?'=>'ja','?'=>'a','?'=>'b','?'=>'g','?'=>'d','?'=>'h','?'=>'v',
'?'=>'z','?'=>'h','?'=>'t','?'=>'i','?'=>'k','?'=>'k','?'=>'l','?'=>'m','?'=>'m','?'=>'n','?'=>'n','?'=>'s','?'=>'e',
'?'=>'p','?'=>'p','?'=>'C','?'=>'c','?'=>'q','?'=>'r','?'=>'w','?'=>'t'
);

$accentsRemoved = strtr( $stringToRemoveAccents , $unwanted_array );

I can't reproduce your problem. I get the expected result.

How exactly are you using mb_detect_encoding() to verify your string is in fact UTF-8?

If I simply call mb_detect_encoding($input) on both a UTF-8 and ISO-8859-1 encoded version of your string, both of them return "UTF-8", so that function isn't particularly reliable.

iconv() gives me a PHP "notice" when it gets the wrongly encoded string and only echoes "F", but that might just be because of different PHP/iconv settings/versions (?).

I suggest to you try calling mb_check_encoding($input, "utf-8") first to verify that your string really is UTF-8. I think it probably isn't.


An improved version of remove_accents() function according to last version Wordpress 4.3 formatting is:

function mbstring_binary_safe_encoding( $reset = false ) {
    static $encodings = array();
    static $overloaded = null;

    if ( is_null( $overloaded ) )
        $overloaded = function_exists( 'mb_internal_encoding' ) && ( ini_get( 'mbstring.func_overload' ) & 2 );

    if ( false === $overloaded )
        return;

    if ( ! $reset ) {
        $encoding = mb_internal_encoding();
        array_push( $encodings, $encoding );
        mb_internal_encoding( 'ISO-8859-1' );
    }

    if ( $reset && $encodings ) {
        $encoding = array_pop( $encodings );
        mb_internal_encoding( $encoding );
    }
}

function reset_mbstring_encoding() {
    mbstring_binary_safe_encoding( true );
}

function seems_utf8( $str ) {
    mbstring_binary_safe_encoding();
    $length = strlen($str);
    reset_mbstring_encoding();
    for ($i=0; $i < $length; $i++) {
        $c = ord($str[$i]);
        if ($c < 0x80) $n = 0; // 0bbbbbbb
        elseif (($c & 0xE0) == 0xC0) $n=1; // 110bbbbb
        elseif (($c & 0xF0) == 0xE0) $n=2; // 1110bbbb
        elseif (($c & 0xF8) == 0xF0) $n=3; // 11110bbb
        elseif (($c & 0xFC) == 0xF8) $n=4; // 111110bb
        elseif (($c & 0xFE) == 0xFC) $n=5; // 1111110b
        else return false; // Does not match any model
        for ($j=0; $j<$n; $j++) { // n bytes matching 10bbbbbb follow ?
            if ((++$i == $length) || ((ord($str[$i]) & 0xC0) != 0x80))
                return false;
        }
    }
    return true;
}

function remove_accents( $string ) {
    if ( !preg_match('/[\x80-\xff]/', $string) )
        return $string;

    if (seems_utf8($string)) {
        $chars = array(
            // Decompositions for Latin-1 Supplement
            chr(194).chr(170) => 'a', chr(194).chr(186) => 'o',
            chr(195).chr(128) => 'A', chr(195).chr(129) => 'A',
            chr(195).chr(130) => 'A', chr(195).chr(131) => 'A',
            chr(195).chr(132) => 'A', chr(195).chr(133) => 'A',
            chr(195).chr(134) => 'AE',chr(195).chr(135) => 'C',
            chr(195).chr(136) => 'E', chr(195).chr(137) => 'E',
            chr(195).chr(138) => 'E', chr(195).chr(139) => 'E',
            chr(195).chr(140) => 'I', chr(195).chr(141) => 'I',
            chr(195).chr(142) => 'I', chr(195).chr(143) => 'I',
            chr(195).chr(144) => 'D', chr(195).chr(145) => 'N',
            chr(195).chr(146) => 'O', chr(195).chr(147) => 'O',
            chr(195).chr(148) => 'O', chr(195).chr(149) => 'O',
            chr(195).chr(150) => 'O', chr(195).chr(153) => 'U',
            chr(195).chr(154) => 'U', chr(195).chr(155) => 'U',
            chr(195).chr(156) => 'U', chr(195).chr(157) => 'Y',
            chr(195).chr(158) => 'TH',chr(195).chr(159) => 's',
            chr(195).chr(160) => 'a', chr(195).chr(161) => 'a',
            chr(195).chr(162) => 'a', chr(195).chr(163) => 'a',
            chr(195).chr(164) => 'a', chr(195).chr(165) => 'a',
            chr(195).chr(166) => 'ae',chr(195).chr(167) => 'c',
            chr(195).chr(168) => 'e', chr(195).chr(169) => 'e',
            chr(195).chr(170) => 'e', chr(195).chr(171) => 'e',
            chr(195).chr(172) => 'i', chr(195).chr(173) => 'i',
            chr(195).chr(174) => 'i', chr(195).chr(175) => 'i',
            chr(195).chr(176) => 'd', chr(195).chr(177) => 'n',
            chr(195).chr(178) => 'o', chr(195).chr(179) => 'o',
            chr(195).chr(180) => 'o', chr(195).chr(181) => 'o',
            chr(195).chr(182) => 'o', chr(195).chr(184) => 'o',
            chr(195).chr(185) => 'u', chr(195).chr(186) => 'u',
            chr(195).chr(187) => 'u', chr(195).chr(188) => 'u',
            chr(195).chr(189) => 'y', chr(195).chr(190) => 'th',
            chr(195).chr(191) => 'y', chr(195).chr(152) => 'O',
            // Decompositions for Latin Extended-A
            chr(196).chr(128) => 'A', chr(196).chr(129) => 'a',
            chr(196).chr(130) => 'A', chr(196).chr(131) => 'a',
            chr(196).chr(132) => 'A', chr(196).chr(133) => 'a',
            chr(196).chr(134) => 'C', chr(196).chr(135) => 'c',
            chr(196).chr(136) => 'C', chr(196).chr(137) => 'c',
            chr(196).chr(138) => 'C', chr(196).chr(139) => 'c',
            chr(196).chr(140) => 'C', chr(196).chr(141) => 'c',
            chr(196).chr(142) => 'D', chr(196).chr(143) => 'd',
            chr(196).chr(144) => 'D', chr(196).chr(145) => 'd',
            chr(196).chr(146) => 'E', chr(196).chr(147) => 'e',
            chr(196).chr(148) => 'E', chr(196).chr(149) => 'e',
            chr(196).chr(150) => 'E', chr(196).chr(151) => 'e',
            chr(196).chr(152) => 'E', chr(196).chr(153) => 'e',
            chr(196).chr(154) => 'E', chr(196).chr(155) => 'e',
            chr(196).chr(156) => 'G', chr(196).chr(157) => 'g',
            chr(196).chr(158) => 'G', chr(196).chr(159) => 'g',
            chr(196).chr(160) => 'G', chr(196).chr(161) => 'g',
            chr(196).chr(162) => 'G', chr(196).chr(163) => 'g',
            chr(196).chr(164) => 'H', chr(196).chr(165) => 'h',
            chr(196).chr(166) => 'H', chr(196).chr(167) => 'h',
            chr(196).chr(168) => 'I', chr(196).chr(169) => 'i',
            chr(196).chr(170) => 'I', chr(196).chr(171) => 'i',
            chr(196).chr(172) => 'I', chr(196).chr(173) => 'i',
            chr(196).chr(174) => 'I', chr(196).chr(175) => 'i',
            chr(196).chr(176) => 'I', chr(196).chr(177) => 'i',
            chr(196).chr(178) => 'IJ',chr(196).chr(179) => 'ij',
            chr(196).chr(180) => 'J', chr(196).chr(181) => 'j',
            chr(196).chr(182) => 'K', chr(196).chr(183) => 'k',
            chr(196).chr(184) => 'k', chr(196).chr(185) => 'L',
            chr(196).chr(186) => 'l', chr(196).chr(187) => 'L',
            chr(196).chr(188) => 'l', chr(196).chr(189) => 'L',
            chr(196).chr(190) => 'l', chr(196).chr(191) => 'L',
            chr(197).chr(128) => 'l', chr(197).chr(129) => 'L',
            chr(197).chr(130) => 'l', chr(197).chr(131) => 'N',
            chr(197).chr(132) => 'n', chr(197).chr(133) => 'N',
            chr(197).chr(134) => 'n', chr(197).chr(135) => 'N',
            chr(197).chr(136) => 'n', chr(197).chr(137) => 'N',
            chr(197).chr(138) => 'n', chr(197).chr(139) => 'N',
            chr(197).chr(140) => 'O', chr(197).chr(141) => 'o',
            chr(197).chr(142) => 'O', chr(197).chr(143) => 'o',
            chr(197).chr(144) => 'O', chr(197).chr(145) => 'o',
            chr(197).chr(146) => 'OE',chr(197).chr(147) => 'oe',
            chr(197).chr(148) => 'R',chr(197).chr(149) => 'r',
            chr(197).chr(150) => 'R',chr(197).chr(151) => 'r',
            chr(197).chr(152) => 'R',chr(197).chr(153) => 'r',
            chr(197).chr(154) => 'S',chr(197).chr(155) => 's',
            chr(197).chr(156) => 'S',chr(197).chr(157) => 's',
            chr(197).chr(158) => 'S',chr(197).chr(159) => 's',
            chr(197).chr(160) => 'S', chr(197).chr(161) => 's',
            chr(197).chr(162) => 'T', chr(197).chr(163) => 't',
            chr(197).chr(164) => 'T', chr(197).chr(165) => 't',
            chr(197).chr(166) => 'T', chr(197).chr(167) => 't',
            chr(197).chr(168) => 'U', chr(197).chr(169) => 'u',
            chr(197).chr(170) => 'U', chr(197).chr(171) => 'u',
            chr(197).chr(172) => 'U', chr(197).chr(173) => 'u',
            chr(197).chr(174) => 'U', chr(197).chr(175) => 'u',
            chr(197).chr(176) => 'U', chr(197).chr(177) => 'u',
            chr(197).chr(178) => 'U', chr(197).chr(179) => 'u',
            chr(197).chr(180) => 'W', chr(197).chr(181) => 'w',
            chr(197).chr(182) => 'Y', chr(197).chr(183) => 'y',
            chr(197).chr(184) => 'Y', chr(197).chr(185) => 'Z',
            chr(197).chr(186) => 'z', chr(197).chr(187) => 'Z',
            chr(197).chr(188) => 'z', chr(197).chr(189) => 'Z',
            chr(197).chr(190) => 'z', chr(197).chr(191) => 's',
            // Decompositions for Latin Extended-B
            chr(200).chr(152) => 'S', chr(200).chr(153) => 's',
            chr(200).chr(154) => 'T', chr(200).chr(155) => 't',
            // Euro Sign
            chr(226).chr(130).chr(172) => 'E',
            // GBP (Pound) Sign
            chr(194).chr(163) => '',
            // Vowels with diacritic (Vietnamese)
            // unmarked
            chr(198).chr(160) => 'O', chr(198).chr(161) => 'o',
            chr(198).chr(175) => 'U', chr(198).chr(176) => 'u',
            // grave accent
            chr(225).chr(186).chr(166) => 'A', chr(225).chr(186).chr(167) => 'a',
            chr(225).chr(186).chr(176) => 'A', chr(225).chr(186).chr(177) => 'a',
            chr(225).chr(187).chr(128) => 'E', chr(225).chr(187).chr(129) => 'e',
            chr(225).chr(187).chr(146) => 'O', chr(225).chr(187).chr(147) => 'o',
            chr(225).chr(187).chr(156) => 'O', chr(225).chr(187).chr(157) => 'o',
            chr(225).chr(187).chr(170) => 'U', chr(225).chr(187).chr(171) => 'u',
            chr(225).chr(187).chr(178) => 'Y', chr(225).chr(187).chr(179) => 'y',
            // hook
            chr(225).chr(186).chr(162) => 'A', chr(225).chr(186).chr(163) => 'a',
            chr(225).chr(186).chr(168) => 'A', chr(225).chr(186).chr(169) => 'a',
            chr(225).chr(186).chr(178) => 'A', chr(225).chr(186).chr(179) => 'a',
            chr(225).chr(186).chr(186) => 'E', chr(225).chr(186).chr(187) => 'e',
            chr(225).chr(187).chr(130) => 'E', chr(225).chr(187).chr(131) => 'e',
            chr(225).chr(187).chr(136) => 'I', chr(225).chr(187).chr(137) => 'i',
            chr(225).chr(187).chr(142) => 'O', chr(225).chr(187).chr(143) => 'o',
            chr(225).chr(187).chr(148) => 'O', chr(225).chr(187).chr(149) => 'o',
            chr(225).chr(187).chr(158) => 'O', chr(225).chr(187).chr(159) => 'o',
            chr(225).chr(187).chr(166) => 'U', chr(225).chr(187).chr(167) => 'u',
            chr(225).chr(187).chr(172) => 'U', chr(225).chr(187).chr(173) => 'u',
            chr(225).chr(187).chr(182) => 'Y', chr(225).chr(187).chr(183) => 'y',
            // tilde
            chr(225).chr(186).chr(170) => 'A', chr(225).chr(186).chr(171) => 'a',
            chr(225).chr(186).chr(180) => 'A', chr(225).chr(186).chr(181) => 'a',
            chr(225).chr(186).chr(188) => 'E', chr(225).chr(186).chr(189) => 'e',
            chr(225).chr(187).chr(132) => 'E', chr(225).chr(187).chr(133) => 'e',
            chr(225).chr(187).chr(150) => 'O', chr(225).chr(187).chr(151) => 'o',
            chr(225).chr(187).chr(160) => 'O', chr(225).chr(187).chr(161) => 'o',
            chr(225).chr(187).chr(174) => 'U', chr(225).chr(187).chr(175) => 'u',
            chr(225).chr(187).chr(184) => 'Y', chr(225).chr(187).chr(185) => 'y',
            // acute accent
            chr(225).chr(186).chr(164) => 'A', chr(225).chr(186).chr(165) => 'a',
            chr(225).chr(186).chr(174) => 'A', chr(225).chr(186).chr(175) => 'a',
            chr(225).chr(186).chr(190) => 'E', chr(225).chr(186).chr(191) => 'e',
            chr(225).chr(187).chr(144) => 'O', chr(225).chr(187).chr(145) => 'o',
            chr(225).chr(187).chr(154) => 'O', chr(225).chr(187).chr(155) => 'o',
            chr(225).chr(187).chr(168) => 'U', chr(225).chr(187).chr(169) => 'u',
            // dot below
            chr(225).chr(186).chr(160) => 'A', chr(225).chr(186).chr(161) => 'a',
            chr(225).chr(186).chr(172) => 'A', chr(225).chr(186).chr(173) => 'a',
            chr(225).chr(186).chr(182) => 'A', chr(225).chr(186).chr(183) => 'a',
            chr(225).chr(186).chr(184) => 'E', chr(225).chr(186).chr(185) => 'e',
            chr(225).chr(187).chr(134) => 'E', chr(225).chr(187).chr(135) => 'e',
            chr(225).chr(187).chr(138) => 'I', chr(225).chr(187).chr(139) => 'i',
            chr(225).chr(187).chr(140) => 'O', chr(225).chr(187).chr(141) => 'o',
            chr(225).chr(187).chr(152) => 'O', chr(225).chr(187).chr(153) => 'o',
            chr(225).chr(187).chr(162) => 'O', chr(225).chr(187).chr(163) => 'o',
            chr(225).chr(187).chr(164) => 'U', chr(225).chr(187).chr(165) => 'u',
            chr(225).chr(187).chr(176) => 'U', chr(225).chr(187).chr(177) => 'u',
            chr(225).chr(187).chr(180) => 'Y', chr(225).chr(187).chr(181) => 'y',
            // Vowels with diacritic (Chinese, Hanyu Pinyin)
            chr(201).chr(145) => 'a',
            // macron
            chr(199).chr(149) => 'U', chr(199).chr(150) => 'u',
            // acute accent
            chr(199).chr(151) => 'U', chr(199).chr(152) => 'u',
            // caron
            chr(199).chr(141) => 'A', chr(199).chr(142) => 'a',
            chr(199).chr(143) => 'I', chr(199).chr(144) => 'i',
            chr(199).chr(145) => 'O', chr(199).chr(146) => 'o',
            chr(199).chr(147) => 'U', chr(199).chr(148) => 'u',
            chr(199).chr(153) => 'U', chr(199).chr(154) => 'u',
            // grave accent
            chr(199).chr(155) => 'U', chr(199).chr(156) => 'u',
        );

        $string = strtr($string, $chars);
    } else {
        $chars = array();
        // Assume ISO-8859-1 if not UTF-8
        $chars['in'] = chr(128).chr(131).chr(138).chr(142).chr(154).chr(158)
            .chr(159).chr(162).chr(165).chr(181).chr(192).chr(193).chr(194)
            .chr(195).chr(196).chr(197).chr(199).chr(200).chr(201).chr(202)
            .chr(203).chr(204).chr(205).chr(206).chr(207).chr(209).chr(210)
            .chr(211).chr(212).chr(213).chr(214).chr(216).chr(217).chr(218)
            .chr(219).chr(220).chr(221).chr(224).chr(225).chr(226).chr(227)
            .chr(228).chr(229).chr(231).chr(232).chr(233).chr(234).chr(235)
            .chr(236).chr(237).chr(238).chr(239).chr(241).chr(242).chr(243)
            .chr(244).chr(245).chr(246).chr(248).chr(249).chr(250).chr(251)
            .chr(252).chr(253).chr(255);

        $chars['out'] = "EfSZszYcYuAAAAAACEEEEIIIINOOOOOOUUUUYaaaaaaceeeeiiiinoooooouuuuyy";

        $string = strtr($string, $chars['in'], $chars['out']);
        $double_chars = array();
        $double_chars['in'] = array(chr(140), chr(156), chr(198), chr(208), chr(222), chr(223), chr(230), chr(240), chr(254));
        $double_chars['out'] = array('OE', 'oe', 'AE', 'DH', 'TH', 'ss', 'ae', 'dh', 'th');
        $string = str_replace($double_chars['in'], $double_chars['out'], $string);
    }

    return $string;
}

My answer is an update of @dynamic solution since Romanian or perhaps other language diacritics weren't converted. I wrote the minimum functions and works like a charm.

print_r(remove_accents('Ia?i, Ia?i County, Romania'));

here is a simple function that i use usually to remove accents :

function str_without_accents($str, $charset='utf-8')
{
    $str = htmlentities($str, ENT_NOQUOTES, $charset);

    $str = preg_replace('#&([A-za-z])(?:acute|cedil|caron|circ|grave|orn|ring|slash|th|tilde|uml);#', '\1', $str);
    $str = preg_replace('#&([A-za-z]{2})(?:lig);#', '\1', $str); // pour les ligatures e.g. '&oelig;'
    $str = preg_replace('#&[^;]+;#', '', $str); // supprime les autres caractères

    return $str;   // or add this : mb_strtoupper($str); for uppercase :)
}

Something like this?

$arrSearch  = explode(","," ,ç,æ, œ, á,é,í,ó,ú,à,è,ì,ò,ù,ä,ë,ï,ö,ü,ÿ,â,ê,î,ô,û,å,e,i,ø,u");

$arrReplace = explode(",","_,c,ae,oe,a,e,i,o,u,a,e,i,o,u,a,e,i,o,u,y,a,e,i,o,u,a,e,i,o,u");

$output = str_replace($arrSearch, $arrReplace, $input);

When using iconv, the parameter locale must be set:

function test_enc($text = 'ešcržýáíé EŠCRŽÝÁÍÉ fóø bår FÓØ BÅR æ')
{
    echo '<tt>';
    echo iconv('utf8', 'ascii//TRANSLIT', $text);
    echo '</tt><br/>';
} 

test_enc();
setlocale(LC_ALL, 'cs_CZ.utf8');
test_enc();
setlocale(LC_ALL, 'en_US.utf8');
test_enc();

Yields into:

????????? ????????? f?? b?r F?? B?R ae
escrzyaie ESCRZYAIE fo? bar FO? BAR ae
escrzyaie ESCRZYAIE fo? bar FO? BAR ae

Another locales then cs_CZ and en_US I haven't installed and I can't test it.

In C# I see solution using translation to unicode normalized form - accents are splitted out and then filtered via nonspacing unicode category.


Merged Cazuma Nii Cavalcanti's implementation with Junior Mayhé's char list, hoping to save some time for some of you.

function stripAccents($str) {
    return strtr(utf8_decode($str), utf8_decode('ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝßàáâãäåæçèéêëìíîïñòóôõöøùúûüýÿAaAaAaCcCcCcCcDdÐdEeEeEeEeEeGgGgGgGgHhHhIiIiIiIiIi??JjKkLlLlLl??LlNnNnNn?OoOoOoŒœRrRrRrSsSsSsŠšTtTtTtUuUuUuUuUuUuWwYyŸZzZzŽž?ƒOoUuAaIiOoUuUuUuUuUu??????'), 'AAAAAAAECEEEEIIIIDNOOOOOOUUUUYsaaaaaaaeceeeeiiiinoooooouuuuyyAaAaAaCcCcCcCcDdDdEeEeEeEeEeGgGgGgGgHhHhIiIiIiIiIiIJijJjKkLlLlLlLlllNnNnNnnOoOoOoOEoeRrRrRrSsSsSsSsTtTtTtUuUuUuUuUuUuWwYyYZzZzZzsfOoUuAaIiOoUuUuUuUuUuAaAEaeOo');
}

This is a piece of code I found and use often:

function stripAccents($stripAccents){
  return strtr($stripAccents,'àáâãäçèéêëìíîïñòóôõöùúûüýÿÀÁÂÃÄÇÈÉÊËÌÍÎÏÑÒÓÔÕÖÙÚÛÜÝ','aaaaaceeeeiiiinooooouuuuyyAAAAACEEEEIIIINOOOOOUUUUY');
}

You could use urlencode. Does not quite do what you want (remove accents), but will give you a url usable string

$output = urlencode ($input);

In Perl I could use a translate regex, but I cannot think of the PHP equivalent

$input =~ tr/áâàå/aaaa/;

etc...

you could do this using preg_replace

$patterns[0] = '/[á|â|à|å|ä]/';
$patterns[1] = '/[ð|é|ê|è|ë]/';
$patterns[2] = '/[í|î|ì|ï]/';
$patterns[3] = '/[ó|ô|ò|ø|õ|ö]/';
$patterns[4] = '/[ú|û|ù|ü]/';
$patterns[5] = '/æ/';
$patterns[6] = '/ç/';
$patterns[7] = '/ß/';
$replacements[0] = 'a';
$replacements[1] = 'e';
$replacements[2] = 'i';
$replacements[3] = 'o';
$replacements[4] = 'u';
$replacements[5] = 'ae';
$replacements[6] = 'c';
$replacements[7] = 'ss';

$output = preg_replace($patterns, $replacements, $input);

(Please note this was typed from a foggy beer ridden Friday after noon memory, so may not be 100% correct)

or you could make a hash table and do a replacement based off of that.


You can use an array key => value style to use with strtr() safely for UTF-8 characters even if they are multi-bytes.

function no_accent($str){
    $accents = array('À' => 'A', 'Á' => 'A', 'Â' => 'A', 'Ã' => 'A', 'Ä' => 'A', 'Å' => 'A', 'à' => 'a', 'á' => 'a', 'â' => 'a', 'ã' => 'a', 'ä' => 'a', 'å' => 'a', 'A' => 'A', 'a' => 'a', 'A' => 'A', 'a' => 'a', 'A' => 'A', 'a' => 'a', 'Ç' => 'C', 'ç' => 'c', 'C' => 'C', 'c' => 'c', 'C' => 'C', 'c' => 'c', 'C' => 'C', 'c' => 'c', 'C' => 'C', 'c' => 'c', 'Ð' => 'D', 'ð' => 'd', 'D' => 'D', 'd' => 'd', 'Ð' => 'D', 'd' => 'd', 'È' => 'E', 'É' => 'E', 'Ê' => 'E', 'Ë' => 'E', 'è' => 'e', 'é' => 'e', 'ê' => 'e', 'ë' => 'e', 'E' => 'E', 'e' => 'e', 'E' => 'E', 'e' => 'e', 'E' => 'E', 'e' => 'e', 'E' => 'E', 'e' => 'e', 'E' => 'E', 'e' => 'e', 'G' => 'G', 'g' => 'g', 'G' => 'G', 'g' => 'g', 'G' => 'G', 'g' => 'g', 'G' => 'G', 'g' => 'g', 'H' => 'H', 'h' => 'h', 'H' => 'H', 'h' => 'h', 'Ì' => 'I', 'Í' => 'I', 'Î' => 'I', 'Ï' => 'I', 'ì' => 'i', 'í' => 'i', 'î' => 'i', 'ï' => 'i', 'I' => 'I', 'i' => 'i', 'I' => 'I', 'i' => 'i', 'I' => 'I', 'i' => 'i', 'I' => 'I', 'i' => 'i', 'I' => 'I', 'i' => 'i', 'J' => 'J', 'j' => 'j', 'K' => 'K', 'k' => 'k', '?' => 'k', 'L' => 'L', 'l' => 'l', 'L' => 'L', 'l' => 'l', 'L' => 'L', 'l' => 'l', '?' => 'L', '?' => 'l', 'L' => 'L', 'l' => 'l', 'Ñ' => 'N', 'ñ' => 'n', 'N' => 'N', 'n' => 'n', 'N' => 'N', 'n' => 'n', 'N' => 'N', 'n' => 'n', '?' => 'n', '?' => 'N', '?' => 'n', 'Ò' => 'O', 'Ó' => 'O', 'Ô' => 'O', 'Õ' => 'O', 'Ö' => 'O', 'Ø' => 'O', 'ò' => 'o', 'ó' => 'o', 'ô' => 'o', 'õ' => 'o', 'ö' => 'o', 'ø' => 'o', 'O' => 'O', 'o' => 'o', 'O' => 'O', 'o' => 'o', 'O' => 'O', 'o' => 'o', 'R' => 'R', 'r' => 'r', 'R' => 'R', 'r' => 'r', 'R' => 'R', 'r' => 'r', 'S' => 'S', 's' => 's', 'S' => 'S', 's' => 's', 'S' => 'S', 's' => 's', 'Š' => 'S', 'š' => 's', '?' => 's', 'T' => 'T', 't' => 't', 'T' => 'T', 't' => 't', 'T' => 'T', 't' => 't', 'Ù' => 'U', 'Ú' => 'U', 'Û' => 'U', 'Ü' => 'U', 'ù' => 'u', 'ú' => 'u', 'û' => 'u', 'ü' => 'u', 'U' => 'U', 'u' => 'u', 'U' => 'U', 'u' => 'u', 'U' => 'U', 'u' => 'u', 'U' => 'U', 'u' => 'u', 'U' => 'U', 'u' => 'u', 'U' => 'U', 'u' => 'u', 'W' => 'W', 'w' => 'w', 'Ý' => 'Y', 'ý' => 'y', 'ÿ' => 'y', 'Y' => 'Y', 'y' => 'y', 'Ÿ' => 'Y', 'Z' => 'Z', 'z' => 'z', 'Z' => 'Z', 'z' => 'z', 'Ž' => 'Z', 'ž' => 'z');
    return strtr($str, $accents);
}

Plus, you save decode/encode in UTF-8 part.