How to Convert Hex to RGB in PHP
- PHP's hexdec() converts a hex string to a decimal integer — use it on each two-character channel.
- Extract channels with substr(): substr($hex, 0, 2) for red, substr($hex, 2, 2) for green, substr($hex, 4, 2) for blue.
- Strip the # prefix first with ltrim($hex, "#").
- Use the free converter above for one-off lookups without writing PHP.
Table of Contents
PHP makes hex-to-RGB conversion straightforward with two built-in functions: substr() to extract each two-character color channel, and hexdec() to convert from hexadecimal to a decimal integer. The result is three integers between 0 and 255 that you can use for CSS output, image processing, or data storage.
A Basic PHP Hex to RGB Function
Clean and production-ready:
function hexToRgb(string $hex): array {
$hex = ltrim($hex, '#');
return [
'r' => hexdec(substr($hex, 0, 2)),
'g' => hexdec(substr($hex, 2, 2)),
'b' => hexdec(substr($hex, 4, 2)),
];
}
$rgb = hexToRgb('#3B82F6');
// ['r' => 59, 'g' => 130, 'b' => 246]
echo "rgb({$rgb['r']}, {$rgb['g']}, {$rgb['b']})";
// rgb(59, 130, 246)
ltrim($hex, '#') removes the hash prefix if present. hexdec() converts any hex string (case-insensitive) to a decimal integer. substr() extracts the two-character slice for each channel.
Using sscanf for a One-Line Approach
PHP's sscanf() function can parse a hex string into three integers in a single call:
$hex = ltrim('#3B82F6', '#');
[$r, $g, $b] = sscanf($hex, '%02x%02x%02x');
// $r=59, $g=130, $b=246
The format string '%02x%02x%02x' reads three two-digit hex values in sequence. This is slightly more compact than the substr/hexdec approach and equally reliable. Both are valid choices.
Returning a CSS rgb() String Directly
If the goal is to generate inline styles or CSS output, return the formatted string directly:
function hexToCss(string $hex): string {
$hex = ltrim($hex, '#');
[$r, $g, $b] = sscanf($hex, '%02x%02x%02x');
return "rgb($r, $g, $b)";
}
echo hexToCss('#FF6400');
// rgb(255, 100, 0)
This is useful when generating HTML templates server-side or when applying dynamic colors to image overlays with the GD library.
Handling Three-Character Hex Shorthand in PHP
Hex shorthand like #F60 needs expansion before parsing:
function normalizeHex(string $hex): string {
$hex = ltrim($hex, '#');
if (strlen($hex) === 3) {
$hex = $hex[0].$hex[0].$hex[1].$hex[1].$hex[2].$hex[2];
}
return $hex;
}
// Usage:
$hex = normalizeHex('#F60'); // 'FF6600'
[$r, $g, $b] = sscanf($hex, '%02x%02x%02x');
Run normalization before any parsing call to handle both three-character and six-character input reliably.
Need a Quick Conversion?
Skip the PHP — paste your hex code above and copy the RGB values in one click.
Open Hex to RGB ConverterFrequently Asked Questions
What does hexdec() do in PHP?
hexdec() converts a hexadecimal string to its decimal (base 10) integer equivalent. hexdec("FF") returns 255, hexdec("3B") returns 59. It is case-insensitive and works on any length hex string.
Is there a built-in PHP function for hex to RGB?
No single built-in function does the full conversion. The combination of ltrim() + substr() + hexdec(), or ltrim() + sscanf(), is the standard pattern used across PHP projects.
Does this work in all PHP versions?
Both hexdec() and sscanf() have been in PHP since version 4. The typed parameter (string $hex) requires PHP 7.0+. For older PHP, remove the type hint: function hexToRgb($hex).
How do I convert RGB back to hex in PHP?
Use sprintf with the %02x format: sprintf("#%02x%02x%02x", $r, $g, $b). The %02x specifier converts an integer to a two-character lowercase hex string, zero-padded if needed.
