URL Encoder & Decoder

What this tool does

Choose Encode to turn text into percent-encoding, for example a space becoming %20 and & becoming %26. Choose Decode to turn it back. The conversion happens as you work, in your browser.

How to use it

1. Choose Encode URL or Decode URL.
2. Paste only the value you want to convert, not the whole address, when you are encoding.
3. Press Copy Output to take the result.

Which rules it uses

Encoding uses JavaScript’s encodeURIComponent. That is the right choice for a single value, such as a query-string parameter or a path segment. It encodes everything except letters, digits and - _ . ! ~ * ' ( ).

That has a consequence worth knowing: if you paste a whole URL, the colons and slashes are encoded too, and you get something like https%3A%2F%2Fexample.com. That is correct for putting a URL inside another URL’s parameter, but not what you want if you just wanted to clean up a link. Encode only the part that is a value.

Decoding treats + as a space before decoding the percent sequences, which is how HTML forms encode spaces in query strings.

Common problems

• Double encoding. If you see %2520, the text was encoded twice. Decode once and check.
• Malformed sequences. A stray % that isn’t followed by two hex digits makes decoding fail with an error.
• Non-ASCII text is encoded as UTF-8 bytes, so é becomes %C3%A9.
• Reserved characters in paths. A / inside a value must be encoded as %2F, or it will be read as a path separator.

When I reach for it

Building a redirect or tracking URL by hand, reading a long encoded link from a log, or checking why a query parameter with & in it is being cut off.