URL decode percent encoded links online

A percent sign in the input is not followed by two hexadecimal digits. Most often the string contains a literal percent that should have been written as %25, or part of the string was truncated in copying.

Because it was encoded twice, which happens when a link passes through two systems that each encode it. Run the output through again; %2520 decoding to %20 and then to a space is the classic signature.

It is converted to a space, matching how form submissions encode query strings. If you needed a literal plus it should have arrived as %2B, which decodes correctly.

Yes. If you want the parts broken out separately, with each query parameter on its own line, use the URL beautifier instead.

No. Decoding happens in the browser, so a URL containing session identifiers or personal data is not transmitted.