How to Encode and Decode a URL in PHP?

Encoding and decoding URLs in PHP are essential tasks when working with web applications, especially for handling user input and constructing query strings. URL encoding ensures that special characters are properly represented in URLs, preventing errors or unexpected behavior during data transmission. PHP provides built-in functions to encode and decode URLs efficiently, allowing developers to manipulate URL components securely.

Approach:

• Using urlencode() Function: The urlencode() function in PHP encodes a string by replacing special characters with their hexadecimal representation preceded by a percent sign (%). This function is typically used to encode query string parameters.
• Using urldecode() Function: The urldecode() function decodes a URL-encoded string, converting hexadecimal representations of special characters back to their original characters. It reverses the encoding performed by urlencode().

Syntax:

// Encoding a URL
$encodedURL = urlencode($url);
// Decoding a URL
$decodedURL = urldecode($encodedURL);

Example: Implementation to encode/decode the URL.

PHP

<?php

// URL to encode
$url = "https://www.geeksforgeeks.org/page.php?query=hello geeks";

// Encoding the URL
$encodedURL = urlencode($url);
echo "Encoded URL: $encodedURL\n";

// Decoding the URL
$decodedURL = urldecode($encodedURL);
echo "Decoded URL: $decodedURL\n";

?>

Output

Encoded URL: https%3A%2F%2Fwww.geeksforgeeks.org%2Fpage.php%3Fquery%3Dhello+geeks
Decoded URL: https://www.geeksforgeeks.org/page.php?query=hello geeks

Features:

• Secure Data Transmission: URL encoding ensures secure transmission of data by properly representing special characters in URLs, preventing interpretation errors or security vulnerabilities.
• Data Integrity: URL decoding allows applications to accurately interpret and process URL-encoded strings, maintaining data integrity during URL manipulation.

Difference between urlencode() and urldecode()

urlencode() Function	urldecode() Function
Encodes a string by replacing special characters with their hexadecimal representation preceded by a percent sign (%)	Decodes a URL-encoded string, converting hexadecimal representations of special characters back to their original characters
Used to encode URL components, such as query string parameters	Employed to decode URL-encoded strings received from external sources
Prevents errors or unexpected behavior in URLs due to special characters or non-ASCII characters	Ensures accurate interpretation of URL-encoded strings, allowing applications to process URL components correctly