Master URL Encoding in PHP: How to Use urlencode and rawurlencode

URL encoding is essential when transmitting data on the internet. When a URL contains special characters (e.g., spaces, ampersand) or non‑ASCII characters (e.g., Chinese, Japanese), it must be encoded to ensure correct transmission and parsing. In PHP, the built‑in urlencode function is used for this purpose.

The urlencode function converts special and non‑ASCII characters into a URL‑safe format. Example for an English string:

<?php
// String to encode
$str = "Hello World!";

// Encode using urlencode
$encodedStr = urlencode($str);

// Output the encoded string
echo $encodedStr;
?>

Running the code outputs the URL‑encoded version of "Hello World!": %48%65%6c%6c%6f%20%57%6f%72%6c%64%21.

When the URL contains non‑ASCII characters, such as Chinese, the same function works:

<?php
// String to encode
$str = "你好，世界！";

// Encode using urlencode
$encodedStr = urlencode($str);

// Output the encoded string
echo $encodedStr;
?>

The result is: %e4%bd%a0%e5%a5%bd%ef%bc%8c%e4%b8%96%e7%95%8c%ef%bc%81.

In real applications, URL encoding is commonly used to pass parameters to a server, for example in GET requests, to preserve data integrity.

Note that urlencode encodes spaces as a plus sign (+). If you need spaces encoded as %20, use the built‑in rawurlencode function instead.

By using PHP’s urlencode (or rawurlencode) you can reliably encode special and non‑ASCII characters in URLs, improving the stability and security of your programs.