122

What would be a good way to convert hex color values like #ffffff into the single RGB values 255 255 255 using PHP?

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11
  • Those two hex's are of the same type? First representing white, the second black... what are you trying to do? Commented Mar 4, 2013 at 12:56
  • $output = sprintf('%06x', 0xffffff - hexdec(ltrim($input, '#')); however that's probably overly simplified and you'll probably want to analyse the RGB components separately, please explain exactly what it is you are wanting to do. Commented Mar 4, 2013 at 12:56
  • Your target representation example (a) doesn't form any representation of a colour I've seen and (b) doesn't meet your "without the #" requirement. Commented Mar 4, 2013 at 12:56
  • #ffffff and #00000 represents White and Black respectively. And for yr information #00000 is also an Hex not an Integer. Here f is representing 15. Commented Mar 4, 2013 at 12:56
  • What do you mean by convert and only using an integer? Commented Mar 4, 2013 at 12:56

18 Answers 18

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385

If you want to convert hex to rgb you can use sscanf:

<?php
$hex = "#ff9900";
list($r, $g, $b) = sscanf($hex, "#%02x%02x%02x");
echo "$hex -> $r $g $b";
?>

Output:

#ff9900 -> 255 153 0
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8 Comments

is there anything so I can have conversion like I asked in my question? Can I have output like #000000
Nice clean approach with the sscanf(), I'm putting that one in my box of magic tricks.
and for shorthand colors (#ccc) : (strlen($hex) === 4) ? list($r, $g, $b) = sscanf($hex, "#%1x%1x%1x") : list($r, $g, $b) = sscanf($hex, "#%2x%2x%2x");
@iiic just writing a test for your one-liner. #ccc will return 12, 12, 12 instead of 204, 204, 204 so if you'd revert it back to hex, you'll get color #0c0c0c.
#F0F translates to #FF00FF so for shorthand colors list($r,$g,$b) = sscanf('#'.implode('',array_map('str_repeat',str_split(str_replace('#','',$hex)), [2,2,2])), "#%02x%02x%02x");
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63

Check out PHP's hexdec() and dechex() functions: http://php.net/manual/en/function.hexdec.php

Example:

$value = hexdec('ff'); // $value = 255
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2 Comments

To use this answer to do a full conversion from a given hex value to rgb, one option is the following: $split_hex_color = str_split( $hex_color, 2 ); $rgb1 = hexdec( $split_hex_color[0] ); $rgb2 = hexdec( $split_hex_color[1] ); $rgb3 = hexdec( $split_hex_color[2] );
To account for 3 or 6 hex value input, you can do $split_hex_color = str_split($hex_color, str_len($hex_color / 3));
54

I made a function which also returns alpha if alpha is provided as a second parameter the code is below.

The function

function hexToRgb($hex, $alpha = false) {
   $hex      = str_replace('#', '', $hex);
   $length   = strlen($hex);
   $rgb['r'] = hexdec($length == 6 ? substr($hex, 0, 2) : ($length == 3 ? str_repeat(substr($hex, 0, 1), 2) : 0));
   $rgb['g'] = hexdec($length == 6 ? substr($hex, 2, 2) : ($length == 3 ? str_repeat(substr($hex, 1, 1), 2) : 0));
   $rgb['b'] = hexdec($length == 6 ? substr($hex, 4, 2) : ($length == 3 ? str_repeat(substr($hex, 2, 1), 2) : 0));
   if ( $alpha ) {
      $rgb['a'] = $alpha;
   }
   return $rgb;
}

Example of function responses

print_r(hexToRgb('#19b698'));
Array (
   [r] => 25
   [g] => 182
   [b] => 152
)

print_r(hexToRgb('19b698'));
Array (
   [r] => 25
   [g] => 182
   [b] => 152
)

print_r(hexToRgb('#19b698', 1));
Array (
   [r] => 25
   [g] => 182
   [b] => 152
   [a] => 1
)

print_r(hexToRgb('#fff'));
Array (
   [r] => 255
   [g] => 255
   [b] => 255
)

If you'd like to return the rgb(a) in CSS format just replace the return $rgb; line in the function with return implode(array_keys($rgb)) . '(' . implode(', ', $rgb) . ')';

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46

For anyone that is interested this is another very simple way of doing it. This example assumes there is exactly 6 characters and no preceding pound sign.

list($r, $g, $b) = array_map('hexdec', str_split($colorName, 2));

Here is an example the supports 4 different inputs (abc, aabbcc, #abc, #aabbcc):

list($r, $g, $b) = array_map(
  function ($c) {
    return hexdec(str_pad($c, 2, $c));
  },
  str_split(ltrim($colorName, '#'), strlen($colorName) > 4 ? 2 : 1)
);
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2 Comments

Use ltrim($colorName, '#') instead of $colorName to take care of a # if it might be there
Wow, your 2nd line of code is incredible... it accepts # or not, and 3 or 6 characters. I think it's the best approach of any code examples on this page. I'm bookmarking this for future projects.
22

You can use the function hexdec(hexStr: String) to get the decimal value of a hexadecimal string.

See below for an example: 

$split = str_split("ffffff", 2);
$r = hexdec($split[0]);
$g = hexdec($split[1]);
$b = hexdec($split[2]);
echo "rgb(" . $r . ", " . $g . ", " . $b . ")";

This will print rgb(255, 255, 255)

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1 Comment

Easier solution to understand and to apply. Tks!
7

Based on the high-rate answer -> https://stackoverflow.com/a/15202130/3884001

function hex2rgba( $color, $opacity ) {

    list($r, $g, $b) = sscanf($color, "#%02x%02x%02x");
    $output = "rgba($r, $g, $b, $opacity)";

    return $output;

}

than you can use it like

<?php
  $color = '#ffffff';
  hex2rgba($color, 0.5); 
?>
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Comments

6

I wrote a simple function like so, which supports an input value with or without beginning # and it can also take 3 or 6 character hex code input:


function hex2rgb( $color ) {

    if ($color[0] == '#') {
        $color = substr($color, 1);
    }
    list($r, $g, $b) = array_map("hexdec", str_split($color, (strlen( $color ) / 3)));
    return array( 'red' => $r, 'green' => $g, 'blue' => $b );
}

This returns an associative array that can be access as $color['red'], $color['green'], $color['blue'];

See also here from CSS Tricks.

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Comments

5

Convert Color Code HEX to RGB

$color = '#ffffff';
$hex = str_replace('#','', $color);
if(strlen($hex) == 3):
   $rgbArray['r'] = hexdec(substr($hex,0,1).substr($hex,0,1));
   $rgbArray['g'] = hexdec(substr($hex,1,1).substr($hex,1,1));
   $rgbArray['b'] = hexdec(substr($hex,2,1).substr($hex,2,1));
else:
   $rgbArray['r'] = hexdec(substr($hex,0,2));
   $rgbArray['g'] = hexdec(substr($hex,2,2));
   $rgbArray['b'] = hexdec(substr($hex,4,2));
endif;

print_r($rgbArray);

Output

Array ( [r] => 255 [g] => 255 [b] => 255 )

I have found this reference from here - Convert Color Hex to RGB and RGB to Hex using PHP

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Comments

5

My approach to take care of hex colors with or without hash, single values or pair values:

function hex2rgb ( $hex_color ) {
    $values = str_replace( '#', '', $hex_color );
    switch ( strlen( $values ) ) {
        case 3;
            list( $r, $g, $b ) = sscanf( $values, "%1s%1s%1s" );
            return [ hexdec( "$r$r" ), hexdec( "$g$g" ), hexdec( "$b$b" ) ];
        case 6;
            return array_map( 'hexdec', sscanf( $values, "%2s%2s%2s" ) );
        default:
            return false;
    }
}
// returns array(255,68,204)
var_dump( hex2rgb( '#ff44cc' ) );
var_dump( hex2rgb( 'ff44cc' ) );
var_dump( hex2rgb( '#f4c' ) );
var_dump( hex2rgb( 'f4c' ) );
// returns false
var_dump( hex2rgb( '#f4' ) );
var_dump( hex2rgb( 'f489' ) );
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Comments

5

Borrowing from @jhon's answer - this will return the rgb in string format with an option for opacity.

function convert_hex_to_rgba($hex, $opacity = 1){
    list($r, $g, $b) = sscanf($hex, "#%02x%02x%02x");
    return sprintf('rgba(%s, %s, %s, %s)', $r, $g, $b, $opacity);
}

convert_hex_to_rgba($bg_color, 0.9) // rgba(2,2,2,0.9)
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4

I've put @John's answer and @iic's comment/idea together into a function which can handle both, the usual hex color codes and the shorthand color codes.

A short explanation:

With scanf I read the r, g and b values from the hex color as strings. Not as hex values like in @John's answer. In case of using shorthand color codes, the r, g and b strings have to be doubled ("f" -> "ff" etc.) before converting them to decimals.

function hex2rgb($hexColor)
{
  $shorthand = (strlen($hexColor) == 4);

  list($r, $g, $b) = $shorthand? sscanf($hexColor, "#%1s%1s%1s") : sscanf($hexColor, "#%2s%2s%2s");

  return [
    "r" => hexdec($shorthand? "$r$r" : $r),
    "g" => hexdec($shorthand? "$g$g" : $g),
    "b" => hexdec($shorthand? "$b$b" : $b)
  ];
}
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Comments

0

try this, it converts its arguments (r, g, b) to hexadecimal html-color string #RRGGBB Arguments are converted to integers and trimmed to 0..255 range

<?php
function rgb2html($r, $g=-1, $b=-1)
{
    if (is_array($r) && sizeof($r) == 3)
        list($r, $g, $b) = $r;

    $r = intval($r); $g = intval($g);
    $b = intval($b);

    $r = dechex($r<0?0:($r>255?255:$r));
    $g = dechex($g<0?0:($g>255?255:$g));
    $b = dechex($b<0?0:($b>255?255:$b));

    $color = (strlen($r) < 2?'0':'').$r;
    $color .= (strlen($g) < 2?'0':'').$g;
    $color .= (strlen($b) < 2?'0':'').$b;
    return '#'.$color;
}
?>

oh and the other way round

# character in the beginning can be omitted. Function returns array of three integers in range (0..255) or false when it fails to recognize color format.

<?php
function html2rgb($color)
{
    if ($color[0] == '#')
        $color = substr($color, 1);

    if (strlen($color) == 6)
        list($r, $g, $b) = array($color[0].$color[1],
                                 $color[2].$color[3],
                                 $color[4].$color[5]);
    elseif (strlen($color) == 3)
        list($r, $g, $b) = array($color[0].$color[0], $color[1].$color[1], $color[2].$color[2]);
    else
        return false;

    $r = hexdec($r); $g = hexdec($g); $b = hexdec($b);

    return array($r, $g, $b);
}
?>
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Comments

0 
//if u want to convert rgb to hex
$color='254,125,1';
$rgbarr=explode(",", $color);
echo sprintf("#%02x%02x%02x", $rgbarr[0], $rgbarr[1], $rgbarr[2]);
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Comments

0 
function RGB($hex = '')
{
    $hex = str_replace('#', '', $hex);
    if(strlen($hex) > 3) $color = str_split($hex, 2);
    else $color = str_split($hex);
    return [hexdec($color[0]), hexdec($color[1]), hexdec($color[2])];
}
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1 Comment

While this code may solve the question, including an explanation of how and why this solves the problem would really help to improve the quality of your post, and probably result in more up-votes. Remember that you are answering the question for readers in the future, not just the person asking now. Please edit your answer to add explanations and give an indication of what limitations and assumptions apply.
0 
Enjoy    

public static function hexColorToRgba($hex, float $a){
        if($a < 0.0 || $a > 1.0){
            $a = 1.0;
        }
        for ($i = 1; $i <= 5; $i = $i+2){
            $rgb[] = hexdec(substr($hex,$i,2));
        }
        return"rgba({$rgb[0]},{$rgb[1]},{$rgb[2]},$a)";
    }
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1 Comment

When answering, it's much more helpful if you explain why this is the preferred solution. The goal is to educate, not merely solve a specific problem.
0

My solution: (Supports short notation)

$color = "#0ab";
$colort = trim( $color );
if( $colort and is_string( $color ) and preg_match( "~^#?([abcdef0-9]{3}|[abcdef0-9]{6})$~ui", $colort ))
{
    if( preg_match( "~^#?[abcdef0-9]{3}$~ui", $colort ))
    {
        $hex = trim( $colort, "#" );
        list( $hexR, $hexG, $hexB ) = str_split( $hex );
        $hexR .= $hexR;
        $hexG .= $hexG;
        $hexB .= $hexB;
    }
    else
    {
        $hex = trim( $colort, "#" );
        list( $hexR, $hexG, $hexB ) = str_split( $hex, 2 );
    }

    $colorR = hexdec( $hexR );
    $colorG = hexdec( $hexG );
    $colorB = hexdec( $hexB );
}

// Test
echo $colorR ."/" .$colorG ."/" .$colorB;
// → 0/170/187
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Comments

0

If you want to get hex to RGB you can follow this:

class RGB
{        
    private $color; //#ff0000
    private $red;
    private $green;
    private $blue;

    public function __construct($colorCode = '')
    {
        $this->color = ltrim($colorCode, '#');
        $this->parseColor();
    }
    public function readRGBColor()
    {
        echo "Red = {$this->red}\nGreen = {$this->green}\nBlue = {$this->blue}";
    }
    private function parseColor()
    {
        if ($this->color) {
            list($this->red, $this->green, $this->blue) = sscanf($this->color, '%02x%02x%02x');
        } else {
            list($this->red, $this->green, $this->blue) = array(0, 0, 0);
        }
    }
}

$myColor = new RGB("#ffffff");
$myColor->readRGBColor();
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Comments

0 
<?php
function cc2rgb($cc) { $cc=ltrim($cc,'#'); return list($r, $g, $b)=array_map('hexdec',str_split($cc,strlen($cc)/3)); }
?>

this is a simple (one line) function, based on many correct previous answer. i don't explain how it works, some guys did it before.

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