URL Encoder and Decoder

URL decoder and URL encoder: what this does

As a URL decoder this turns percent-escaped text back into what it stood for, so hello%20world%3F reads as hello world? again. Run the other way it is a URL encoder, replacing the characters that would otherwise end a path or split a query. Both directions are percent encoding, sometimes written urlencode after the function many languages give it. To URL decode or URL encode here, pick the direction, paste your text, and read the result — nothing is uploaded.

Choose the profile for your data

JavaScript component matches encodeURIComponent and decodeURIComponent for one value. Full URI preserves URL structure and escaped reserved delimiters while decoding. RFC 3986 component uses the stricter unreserved set. Form value uses plus for spaces and a distinct punctuation set; it encodes a single value, rather than assembling a full form body.

Why %20, plus and %25 differ

A space becomes %20 in component encoding and + in form encoding. A literal plus becomes %2B. Decoding + outside form mode keeps the plus. Encoding an existing percent escape encodes its percent sign again, so %20 becomes %2520. The tool offers an explanation rather than silently repairing your input.

Unicode and precise errors

Percent escapes represent UTF-8 bytes. The character é uses %C3%A9; an emoji can use four bytes and two UTF-16 units. Counts distinguish scalars, UTF-16 units and UTF-8 bytes. Invalid escapes and malformed Unicode stop conversion while preserving input. Error line/column uses UTF-16 columns; CRLF counts as one line break. Later-pass errors name their intermediate coordinate space.

Inspecting query parameters

Query separators are split before decoding, so %26 stays inside one value. Repeated names, empty names, empty values and flags without an equals sign remain visible. Malformed cells retain their raw text and an error, while conversion results remain all-or-nothing. Parsed URL display describes browser parsing, not whether a destination exists or is safe.

URL decode and encode in code

The same conversion in the languages people usually reach for: JavaScript (js) decodeURIComponent(s) and encodeURIComponent(s); Python urllib.parse.unquote(s) and quote(s); PHP rawurldecode($s) and rawurlencode($s); Java URLDecoder.decode(s, UTF_8). Each matches a profile above — pick the form-encoded variant when a plus sign should mean a space, as it does in a submitted form but not in a path.

Local processing and limits

Text stays in browser memory. Copy, downloads and optional result printing are explicit actions. The source limit is 262,144 UTF-16 units; files are UTF-8 text up to 1 MiB, subject to that source limit. Batches and query tables support 1,000 records; repeated decoding is limited to five passes. Undo is bounded to 20 snapshots and 1,048,576 source units. Large output uses a labelled preview and complete copy/TXT. URL encoding is reversible representation, not encryption.

Standards: ECMAScript URI functions, RFC 3986 and WHATWG form encoding.

Base64 encoder and decoder · JSON formatter and validator