encodeURIComponent encodes everything except letters, digits, and - _ . ! ~ * ' ( ) — use it for query parameter values. encodeURI preserves URL structure characters like :, /, ?, and & — use it for full URLs. This tool works entirely in your browser.
Encode or decode URLs and query strings using percent encoding, with both encodeURIComponent and encodeURI modes.
Everything runs locally in your browser — nothing is sent to a server.
Percent encoding is the URL-safe representation where special characters are replaced with a percent sign followed by their hex byte value. For example, a space becomes %20 and an ampersand becomes %26.
encodeURIComponent encodes everything, including URL-structure characters like /, ?, and & — use it for individual query parameter values. encodeURI preserves those characters — use it for a complete URL that is already well-formed.
Those are the percent-encoded forms of & and =. They appear when a URL was encoded twice or when a parameter value itself contains characters that have meaning in a URL. Decoding once will restore the original characters.