URL encoding, also called percent-encoding, replaces unsafe or reserved characters in URLs with a percent sign followed by two hex digits. For example, a space becomes %20 and an ampersand becomes %26. This ensures that URLs are transmitted correctly across the internet without ambiguity.
URL encoding is essential when building query strings, passing data in URL parameters, constructing API requests, or handling form submissions. Characters like spaces, ampersands, question marks, and non-ASCII characters all need to be encoded to work correctly in URLs.
Frequently Asked Questions
What characters does URL encoding change?
URL encoding converts reserved characters (like &, =, ?, #, /, +) and unsafe characters (like spaces and non-ASCII characters) into percent-encoded format such as %20 for spaces.
What is the difference between encodeURI and encodeURIComponent?
encodeURI encodes a full URI but preserves characters like :, /, and ? that are valid in URLs. encodeURIComponent encodes everything except letters, digits, and a few special characters, making it ideal for query parameter values.
Why do I see + instead of %20 for spaces sometimes?
The plus sign for spaces is used in application/x-www-form-urlencoded format, which is the default for HTML form submissions. In standard URL encoding (RFC 3986), spaces are encoded as %20.
Can this tool handle Unicode characters?
Yes, the tool correctly handles Unicode characters by encoding them as UTF-8 byte sequences represented in percent-encoded format.
Is my data stored anywhere?
No. All encoding and decoding happens entirely in your browser using JavaScript. No data is sent to any server.