URL decoding reverses percent-encoding, turning sequences like %20 or %3F back into their original characters (a space, a question mark). This is what a browser or server does automatically when reading a query string — this tool lets you do the same thing manually, to inspect what a URL parameter, webhook payload, or log entry actually contains.
It's especially useful when debugging a link that looks garbled, or when a value was encoded more than once ("double-encoded") and needs to be decoded twice to reach its original form.
This tool decodes using decodeURIComponent. Malformed input — such as a lone % not followed by two hex digits — is reported as an error rather than silently producing garbage.
Why does decoding fail on my input?
A malformed percent sequence (like a stray % not followed by two hex digits) will throw an error; make sure the input is validly percent-encoded.
Does this decode + as a space?
No — this tool decodes standard percent-encoding only; + is left as a literal plus sign, matching decodeURIComponent behavior (form-encoded + needs to be replaced with a space first).
Is the decoded text sent anywhere?
No — decoding happens entirely in your browser.