URL Encoder / Decoder

Features

• Component and full-URL encoding modes
• Decoding with clear errors on malformed input
• Complete URL breakdown: scheme, host, path, query, fragment
• Query parameter table with decoded values
• Line-by-line batch processing

How to use it

1. Pick whether you are encoding a component or a whole URL.
2. Paste your text or URL.
3. The result and breakdown update as you type.
4. Copy the result or feed it back in with Swap.

encodeURI versus encodeURIComponent

These two functions are not interchangeable and picking the wrong one is a routine source of bugs. encodeURI assumes you are handing it a complete URL, so it leaves the structural characters alone: : / ? # [ ] @ ! $ & ' ( ) * +; = all survive. That is correct for a whole URL and wrong for a value inside one.

encodeURIComponent escapes all of those. Use it for anything that goes into a URL, a query parameter value, a path segment, a fragment. If a search term contains an ampersand and you encode it with encodeURI, the ampersand stays literal and the server reads the rest of your term as a separate parameter. Encoded as %26, it arrives intact.

Two details that catch people out. Neither function escapes !'()*, which are legal in URLs but occasionally problematic in specific contexts. And a space becomes %20 in both, whereas in the application/x-www-form-urlencoded body of a form submission a space becomes +. When decoding form data you must convert + back to a space first, or decodeURIComponent will leave plus signs scattered through your text.