Using PHP urlencode() and urldecode() Functions for URL Encoding and Decoding

In PHP, URL encoding and decoding are common operations that convert special characters in a URL to their encoded values and back.

PHP offers a set of functions for this purpose; the most frequently used are urlencode() and urldecode() , which are demonstrated with code examples below.

1. urlencode() function

The urlencode() function encodes a string for use in a URL. Its syntax is:

string urlencode(string $str)

Example:

$url = "https://www.example.com/index.php?id=123&name=John Doé";
$encoded_url = urlencode($url);
echo $encoded_url;
// Output: https%3A%2F%2Fwww.example.com%2Findex.php%3Fid%3D123%26name%3DJohn+Do%C3%A9

The example shows a URL containing spaces and non‑ASCII characters being correctly encoded.

2. urldecode() function

The urldecode() function decodes an encoded URL back to its original form. Its syntax is:

string urldecode(string $str)

Example:

$encoded_url = "https%3A%2F%2Fwww.example.com%2Findex.php%3Fid%3D123%26name%3DJohn+Do%C3%A9";
$decoded_url = urldecode($encoded_url);
echo $decoded_url;
// Output: https://www.example.com/index.php?id=123&name=John Doé

This demonstrates that the encoded characters are restored to their original representation.

Besides urlencode() and urldecode() , PHP also provides rawurlencode() and rawurldecode() , which behave similarly but differ slightly in how they treat certain characters.

Using these functions ensures that special characters in URLs are handled correctly, preventing broken links or query‑parameter errors in real‑world applications.