๐ URL Encode/Decode
Percent-encode (URL-encode) text or a URL, or decode it back. Useful for preparing a string to use inside a URL, or inspecting query parameters.
How to use
- Choose "Encode" or "Decode" mode.
- Choose the "Component" or "Full URL" scope.
- Paste your text or URL into the input box and click the run button.
How the calculation works
URLs may contain only letters, digits and a limited set of symbols. To include Japanese text, spaces or characters with special meaning, each character is converted to UTF-8 bytes and each byte written as "%" followed by two hex digits. This is percent-encoding, defined in RFC 3986. The tool has two modes. "Whole URL" uses JavaScript's encodeURI, which leaves characters that give a URL its structure โ "/", "?", "&", "=", "#", ":" โ alone and encodes everything else. "Component" uses encodeURIComponent, which encodes those symbols too. Use component mode when inserting text into part of a URL, such as a query parameter value; otherwise an "&" inside the value would be mistaken for a parameter separator.
Worked example
Encoding "ๆฑไบฌ & ๅคง้ช?x=1" in component mode %E6%9D%B1%E4%BA%AC%20%26%20%E5%A4%A7%E9%98%AA%3Fx%3D1 "ๆฑ" is three bytes in UTF-8, giving three groups, %E6%9D%B1; the space becomes %20 and & becomes %26. Encoding "https://example.com/ๆค็ดข?q=ๆฑไบฌ ๅคง้ช&page=1" in whole-URL mode encodes only the Japanese and the space, leaving "?", "=" and "&" intact.
Things to be aware of
- Use component mode when encoding a query parameter value.
- Form submissions may encode spaces as "+" (application/x-www-form-urlencoded). This tool encodes spaces as %20.
- Decoding malformed percent-encoding (such as "%" not followed by two hex digits) produces an error.
- Encoding an already encoded string turns "%" into %25, double-encoding it.
FAQ
Does the result differ between "component" and "full URL" modes?
Yes โ "component" mode encodes everything including / and &, while "full URL" mode preserves characters that are already valid in a URL. Choose based on what you need.
Can it encode URLs containing Japanese?
Yes โ multi-byte characters like Japanese are converted to UTF-8 percent-encoding.
How do I inspect the contents of a query string?
Paste the encoded query string into Decode mode to see it converted back to readable text.
Are spaces encoded as %20 or +?
Following standard percent-encoding, spaces are encoded as %20.
Is my input sent to a server?
No, encoding and decoding happen entirely in your browser and nothing is sent externally.