This tool encodes and decodes URLs with percent-encoding, the format that turns spaces, accented letters and symbols into sequences such as %20 or %C3%B1 so they travel safely in a web address. It also includes a parser that splits a URL into protocol, host, port, path, fragment and query parameters.
It is handy for developers, for anyone building campaign links with UTM parameters, or for making sense of a long URL copied from an email. Everything runs in your browser.
How to use
- 1Choose “Encode” or “Decode”.
- 2Pick the mode: component (for parameters) or full URL.
- 3Paste the text and copy the result; enable “+ as space” for form data.
- 4Use the parser to view and edit a URL's parameters and rebuild it.
What you can do
- encodeURIComponent and encodeURI
- Decoding with error detection
- Breakdown of protocol, host, path and parameters
encodeURIComponent vs encodeURI
encodeURIComponent encodes every reserved character (/, ?, &, =, #…) and is the right choice for a parameter value. encodeURI leaves those characters alone and is for encoding a full URL without breaking its structure. Using the wrong mode is the most common cause of broken links.
The + sign and spaces
In HTML forms (application/x-www-form-urlencoded) spaces are encoded as + instead of %20. Enable “Treat + as space” to decode data coming from a form or from some APIs correctly.
URL parser
Paste any address to see its parts separately and a table of already-decoded parameters. You can edit, add or remove parameters and the tool rebuilds the URL with correct encoding.
- Review and clean up marketing UTM parameters.
- Debug API calls with many parameters.
- Find out where a redirect URL actually points.
Frequently asked questions
What is URL encoding?
Percent-encoding: every character not allowed in a URL is replaced by % followed by its hexadecimal (UTF-8) code. For example, a space is %20 and ñ is %C3%B1.
Why does decoding fail?
Because the input has a malformed % sequence, such as a lone % or bytes that are not valid UTF-8. The tool tells you the input is invalid instead of returning garbled text.
When should I use %20 and when +?
%20 is valid anywhere in a URL. + only means a space in the query part of form submissions; in the path, + is a literal plus sign.
Does my data leave the browser?
No. Encoding and parsing happen locally.