URL Encoder / Decoder

The URL Encoder/Decoder converts strings to and from percent-encoded form (RFC 3986). Percent encoding is how URLs safely carry characters that would otherwise be reserved or unsafe — spaces become `%20`, ampersands in a query value become `%26`, and Unicode characters get their UTF-8 bytes encoded byte-by-byte as `%XX` pairs.

Developers hit URL encoding constantly — building query strings by hand, embedding user input in redirect URLs, passing JSON through URL parameters, and debugging why a query parameter is being misinterpreted by a downstream service. This tool exposes both the JavaScript `encodeURIComponent` (encode everything except unreserved chars) and `encodeURI` (preserve URL structure) behaviors, so you can pick the right one for your context.

Common gotchas: encoding an already-encoded value produces double-encoded garbage. Servers behind CDNs and reverse proxies may decode once at the edge and pass a partially-decoded value to the origin. Percent-encoded plus signs (`%2B`) and literal plus signs behave differently in some form-decoders — the difference between path segments and query strings matters here.