URL Encode & Decode — Free Online Tool

URL encoding (percent-encoding) replaces unsafe or reserved characters with a percent sign followed by two hex digits. For example, a space becomes %20 and an ampersand becomes %26.

encodeURI preserves characters that are part of URL structure — colons, slashes, question marks, hashes, and ampersands. encodeURIComponent encodes everything except unreserved characters (letters, digits, -, _, ., ~). Use encodeURIComponent for query parameter values and encodeURI for complete URLs.

Anytime you put user input into a URL — query parameters, path segments, or fragment identifiers. Without encoding, special characters like & or = can break the URL structure or cause security issues.

No. All encoding and decoding happens in your browser using native JavaScript APIs. Nothing is transmitted over the network.

Decoding fails when the input contains invalid percent-encoded sequences like %ZZ (Z is not a valid hex digit). Valid percent-encoding uses only digits 0-9 and letters A-F after the percent sign.