Using PHP rawurldecode() to Decode URL‑Encoded Strings

In web development, we often need to handle URLs, and special characters in URLs must be encoded to be correctly transmitted and parsed. In some cases we need to decode URLs, restoring the encoded string to the original URL. PHP provides a set of functions to handle URL encoding and decoding, one of which is the rawurldecode() function.

The rawurldecode() function decodes a URL‑encoded string back to the original URL. It is mainly used to decode strings encoded by the urlencode() function for processing and display.

Below is the syntax of the rawurldecode() function:

string rawurldecode ( string $str )

Here, $str represents the URL string to be decoded, and the function returns the decoded string.

Below is a code example showing how to use the rawurldecode() function for URL decoding:

<?php
$url = "https%3A%2F%2Fwww.example.com%2F%3Fq%3D%D0%B4%D0%BE%D0%B1%D1%80%D1%8B%D0%B9%E6%B1%89%E5%AD%97"; // URL encoded by urlencode()
$decodedUrl = rawurldecode($url);
echo $decodedUrl;
?>

In the above example, a URL is encoded with urlencode() and assigned to $url , then rawurldecode() decodes it. Finally, the echo statement outputs the decoded URL string.

Running the code produces the following output:

https://www.example.com/?q=добрый汉字

We can see that after decoding the encoded URL string with rawurldecode() , we obtain the original URL string.

Note that rawurldecode() only decodes special characters in the URL; it does not process other characters in URL parameters. To decode an entire URL, you can use the urldecode() function.

In summary, rawurldecode() is a convenient PHP function for decoding URLs. It decodes strings encoded by urlencode() back to the original URL. In web development it is often used to handle URL encoding and decoding, ensuring correct transmission and parsing of URL parameters.