URL Component Decoder

What this decoder expects

Paste one encoded component value, such as the contents of a query parameter, rather than assuming the entire URL is one component. The browser’s decodeURIComponent function restores percent escapes and UTF-8 text. If the value includes an incomplete percent sequence or invalid encoding, the operation returns an error.

Some form-style query conventions encode spaces as plus signs, while component encoding represents them as percent escapes. Plus handling therefore depends on the surrounding URL format. If your source is a full query string, parse the parameters with a URL API rather than decoding the entire query indiscriminately.

Decoding is not security validation

Decoded text is untrusted input. A readable string might still contain HTML markup, script-like content, a misleading address, or values unsafe for a shell or database. Decoding only restores a representation; it does not sanitize or authorize. Apply context-appropriate validation at the destination.

Never paste credentials into an unknown URL value just because it looks encoded. Percent-encoding does not hide information and can be reversed without a key.

Verify with the matching encoder

For a controlled test, encode a harmless phrase with the URL Component Encoder, then decode it here and compare every character. Keep delimiters outside the value when constructing a URL. The FormatInstant guides explain the boundary between data values and URL structure.