Don't double-encode. Encoding an already-encoded string turns %20 into %2520 . If your input shows %XX sequences, decode first. Spaces aren't always %20 . In application/x-www-form-urlencoded bodies, spaces are + . This tool follows the JavaScript encodeURIComponent convention (always %20 ); decode handles both. UTF-8 vs Latin-1. Modern browsers and encodeURIComponent always use UTF-8. Some older systems still produce Latin-1 percent-escapes — those won't round-trip cleanly here. Reserved characters are case-insensitive in the percent-escape but case-sensitive in the decoded result — %2F and %2f both decode to / , but the original character's case is preserved.

Encodeur / Décodeur URL

Encodez en pourcentage pour URLs ou décodez vers texte brut.

Mode

Scope

Entrée

Sortie

Saisissez une entrée ci-dessus pour voir le résultat.

What URL encoding does

URLs and HTTP headers are restricted to a small ASCII subset. Anything outside that set — including spaces, accented letters, emoji, and several reserved punctuation characters — has to be percent-encoded: replaced by % followed by two hex digits per byte. café becomes caf%C3%A9 (UTF-8). Decoding reverses that.

When to use which scope

Component — pick this for individual values you'll splice into a URL: query-string values, path segments, fragment text, header values. Encodes the structural characters / ? # & = + so they don't accidentally end up parsed as URL syntax.
Full URI — pick this for a whole URL you want to clean up. Preserves / ? # & = + as URL structure, only encodes illegal characters (spaces, non-ASCII, etc.).

Common gotchas

Don't double-encode. Encoding an already-encoded string turns %20 into %2520. If your input shows %XX sequences, decode first.
Spaces aren't always %20. In application/x-www-form-urlencoded bodies, spaces are +. This tool follows the JavaScript encodeURIComponent convention (always %20); decode handles both.
UTF-8 vs Latin-1. Modern browsers and encodeURIComponent always use UTF-8. Some older systems still produce Latin-1 percent-escapes — those won't round-trip cleanly here.
Reserved characters are case-insensitive in the percent-escape but case-sensitive in the decoded result — %2F and %2f both decode to /, but the original character's case is preserved.