URL Encoder / Decoder

URLs can only contain a limited set of ASCII characters. Special characters like spaces, ampersands, question marks, and non-ASCII characters (accented letters, emoji, CJK characters) must be percent-encoded — replaced with % followed by their hexadecimal byte value.

For example, a space becomes %20, an ampersand becomes %26, and the Japanese character あ becomes %E3%81%82 (its UTF-8 bytes). Without encoding, these characters would break URL parsing — a & would be interpreted as a query parameter separator instead of a literal character.

This tool uses JavaScript's encodeURIComponent() for encoding and decodeURIComponent() for decoding. These functions handle the full Unicode range and are the standard way to prepare values for URL query strings, form submissions, and API requests.