Free URL Encoder/Decoder (Percent Encoding)

encodeURI() preserves URL structure characters like :, /, ?, #, @. Use it for complete URLs. encodeURIComponent() encodes everything except alphanumerics and -_.~. Use it for query parameter values.

%20 is the URL-encoded form of a space character. URLs cannot contain actual spaces, so they must be encoded. When the URL is processed, %20 is automatically converted back to a space.

Use %20 for URL paths and modern applications. The + for space convention comes from HTML form submissions (application/x-www-form-urlencoded) and may not work everywhere. %20 is universally compatible.

Double encoding happens when already-encoded text is encoded again. For example, %20 becomes %2520. This breaks URLs and is a common bug. Always decode first if you are unsure whether text is already encoded.

No, you typically only encode query parameter values or path segments with special characters. Encoding the entire URL (including the protocol and slashes) would break it.

International characters are first converted to UTF-8 bytes, then each byte is percent-encoded. For example, é becomes %C3%A9. Modern browsers handle this automatically in the address bar.