What it is
The URL Encoder and Decoder converts text to and from percent-encoding, the format URLs use to carry characters that would otherwise break them.
Why URLs need encoding at all
A URL can only contain a limited set of characters. Everything else has to be written as a percent sign followed by its hexadecimal code: a space becomes %20, an ampersand becomes %26, an accented letter becomes two or three of these in a row.
That is not decoration. Some characters are structural: & separates parameters, = splits a name from a value, ? starts the query string, # starts a fragment. A search term containing an ampersand, pasted in raw, silently becomes two parameters and the value is truncated at exactly that point. It is one of the quietest bugs there is, because nothing errors: the wrong data simply arrives.
How to use it
- Paste the text or the encoded string.
- Choose encode or decode.
- Copy the result.
Where this comes up
Building a query string by hand. Reading a redirect URL that has another URL nested inside it. Debugging a form submission. Making sense of a tracking link. Fixing accented characters that arrived as %C3%A7 in a log.
Note that the whole thing runs in your browser, so a URL containing a token or a session identifier is not sent anywhere.
Nothing is uploaded
The whole operation runs inside your browser. Your file is never sent to a server, never stored and never seen by anyone else. No queue, no daily cap and no account.