Encode or decode URL components, whole URIs or form values locally. Choose the right treatment for reserved characters and plus signs, then copy or download plain-text results.
All conversion uses local browser functions and a shared site codec, with no uploads, accounts, dependencies or input storage. Decoded text is displayed in a readonly editor and never interpreted as markup, navigated to or executed.
Use a component mode for one query parameter value or path segment. JavaScript component mode uses encodeURIComponent; RFC 3986 component mode additionally escapes !, apostrophe, parentheses and *. Whole URI uses encodeURI and decodeURI, retaining URL structural separators. Form value uses application/x-www-form-urlencoded rules for one value, with + for spaces. It does not parse or construct an entire query string.
Component and whole-URI decoding preserve literal + signs. Spaces encode as %20 in those modes. Form-value encoding converts spaces to + and literal plus signs to %2B. Form decoding converts + to a space before percent-decoding. A form value containing a=b&c=d is treated as one string, not multiple fields.
decodeURI intentionally leaves escaped structural characters such as slash, question mark, ampersand and hash encoded, while decodeURIComponent decodes them. Whole URI mode is the browser’s JavaScript operation, not URL normalization or validation: it can encode square brackets and does not perform hostname-to-punycode conversion. Build dynamic components separately when assembling URLs.
No. It runs one strict decoding pass, rejecting malformed percent escapes or invalid percent-encoded UTF-8. Form-value decoding is intentionally stricter than the forgiving URLSearchParams parser. For example, %252F decodes once to %2F. Encoding existing percent escapes encodes the percent sign again, so choose the operation deliberately.
No trimming or Unicode normalization occurs. Native UTF-8 percent encoding is used; unpaired surrogate units are rejected. The codec preserves literal line endings, while browser textareas normalize pasted CRLF/CR to LF. Decoded markup remains plain text. Encoding is neither encryption nor URL sanitization, and decoded links are never opened automatically.
Encoding accepts 50,000 UTF-16 text units and decoding accepts 500,000. Over-limit or malformed input returns an error without truncation or partial output. Empty results have no download. Clear keeps selected settings; Example loads an example for the current mode and direction. Inputs and results are not uploaded or saved. The existing Text Encoder/Decoder shares component-mode behavior.
