HTML URL Encoding

Understanding URL Encoding

URL encoding, also known as percent encoding, is a method of encoding special characters in URLs to ensure they are transmitted correctly over the internet. URLs can only contain a limited set of characters from the ASCII character set. Any character outside this safe set must be encoded using a percent sign followed by two hexadecimal digits representing the character's ASCII code.

Common characters that require encoding include spaces, punctuation marks, and special symbols. For example, a space character can be encoded as either %20 or a plus sign (+). Understanding URL encoding is essential when working with query strings, form submissions, and API requests that pass data through URLs.

URL encoding ensures that your web applications can handle international characters, special symbols, and reserved characters without breaking functionality. Reserved characters like ampersands (&), question marks (?), and equal signs (=) have special meaning in URLs, so they must be encoded when used as actual data values rather than URL structure delimiters.

Use the interactive tool below to encode and decode URLs easily. The reference table shows commonly encoded characters and their percent-encoded equivalents, helping you understand how different characters are represented in valid URLs.