このツールとは？
The URL encoder/decoder converts special characters in a URL to percent-encoding (e.g. space to %20), or decodes an encoded URL back to readable form.
なぜ使う？
Useful when building links with non-ASCII or spaces, or when interpreting encoded URLs.
使い方
Enter a URL or text, then click "Encode" or "Decode". Copy the result for use in links or API calls.
Processing is done only in the browser; input is not sent to the server.