What is URL Encoding?
URL encoding, also known as percent-encoding, is a method for transforming characters in a Uniform Resource Locator (URL) into a format that can be universally understood and transmitted over the internet. URLs can only contain a specific set of characters from the US-ASCII character set. URL encoding comes into play when a URL needs to include characters that fall outside this allowed set.
How does it work?
• Unsafe Characters: Certain characters are considered unsafe in URLs because they have special meanings within the URL structure (like "/" for separating directories or "?" for initiating a query string). Spaces are another example of an unsafe character.
• Encoding Process: When a URL encounters an unsafe character, it applies URL encoding. The character is converted into its corresponding byte value in UTF-8 (a character encoding that can represent a wider range of characters).
• Hexadecimal Conversion: Each byte value from the UTF-8 conversion is then translated into a two-digit hexadecimal number (using base-16).
• Percent Sign Prefix: The hexadecimal digits representing the byte value are prefixed with a percent sign (%) to indicate that it's an encoded character.
Why is URL Encoding Important?
• Universal Understanding: By encoding unsafe characters, URLs become readable and interpretable by all web browsers and servers regardless of their locale.
• Data Integrity: Encoding ensures that the data within the URL remains intact during transmission across the internet.
Things to Remember About URL Encoding
• Not all characters need encoding. Letters, numbers, hyphens, underscores, and periods are generally safe characters in URLs.
• Decoding a URL-encoded string is straightforward. The percent sign and following hexadecimal digits are converted back into their corresponding character using the UTF-8 encoding scheme.
• There are online tools and libraries available in various programming languages to perform URL encoding and decoding.