Percent-encoding is the reason URLs survive spaces, accents, emoji, and every other character the original URL spec never imagined. The Gizmo 421 URL Encoder converts text to strict percent-encoded form, decodes it back, and handles internationalized domains with real punycode — all in your browser.
Strict versus URL-safe encoding
Encode (strict) escapes everything that is not a plain letter, digit, or a handful of safe symbols — use it for query string values, where a stray & or = would break parsing. Encode URL (keep ://) preserves the URL structure characters (:/?#[]@) so a full address stays readable — use it on whole URLs, not their parameter values. The decode buttons are the same pair in reverse, with friendly errors when the input has a stray percent sign or a truncated sequence.
What punycode is for
Domain names with non-ASCII characters — münchen.de, 日本.jp — are actually stored and resolved as ASCII look-alikes: xn--mnchen-3ya.de, xn--wgv71a.jp. That encoding is called punycode (RFC 3492). This tool implements the real algorithm, both directions, so you can check exactly what a browser sends for an internationalized domain, or decode a suspicious xn-- address you found in a log or a phishing email — where seeing the true characters is half the diagnosis.
Common questions
Is %20 the same as +? In query strings, historically yes — but percent-encoding is the modern, unambiguous choice and what this tool produces. Why does my encoded output differ from some other tool? Most tools escape spaces as +; we follow the current standard. Can it decode binary garbage? It decodes any well-formed percent sequence; malformed input gets an explanation instead of a crash.