Web & URLs
URL Encoder & Decoder
Encode and decode URL components, complete URLs, and form values with batch line processing.
Each action runs exactly one encode or decode pass; percent signs are never processed recursively.
How to use this URL codec
Choose encode or decode, then select the mode that matches your data. Component mode is for one parameter, complete URL mode preserves path and query delimiters, and form mode follows application/x-www-form-urlencoded. Enable line processing to handle several values at once; all calculations happen in your browser.
Reserved characters and plus signs
Component mode escapes reserved characters, while complete URL mode keeps URL structure characters. Form mode encodes spaces as plus signs and converts only unescaped plus signs back to spaces; plus signs remain plus signs in component and complete URL modes.
Frequently asked questions
How are malformed percent escapes handled?
The tool rejects an isolated percent sign, non-hex escapes, and invalid UTF-8, then reports the exact line and column instead of silently returning a partial result.
Why does a plus sign become a space in form mode?
That is the application/x-www-form-urlencoded rule. To represent a literal plus, encode it as <code>%2B</code>; component and complete URL modes leave plus signs unchanged.
Does the tool decode twice automatically?
No. Each action runs once: decoding <code>%2520</code> produces <code>%20</code>. Review the result before deliberately running another pass.