URL Encoder

URL encoding is a mechanism used to translate special characters (like spaces, slashes, or ampersands) into a representation that is safe for transmission over the internet within a URL. Characters are replaced with a percentage sign (%) followed by a two-digit hexadecimal representation of their ASCII code.

encodeURI is designed to encode a full, complete URL. It keeps domain names, query structure, and path separators intact (like /, ?, &, =, #). encodeURIComponent is designed to encode a single query parameter or path segment, meaning it will aggressively encode all characters including slashes, question marks, and ampersands so they don't break the URL syntax.

Standard JavaScript encodeURIComponent does not encode certain characters like !, ', (, ), and * because they are technically safe in some contexts. Strict RFC 3986 mode forces percent-encoding of these characters as well, ensuring absolute compatibility across strict server APIs.

In standard query strings (application/x-www-form-urlencoded format), spaces are historically encoded as a plus sign (+) instead of %20. Some back-end systems expect spaces as + in form submissions or query parameters.

Yes. All percent-encoding happens entirely inside your browser using client-side JavaScript. None of the text you type or URLs you copy are sent to our servers.

URLs can only be sent over the Internet using the ASCII character-set. If a URL contains characters outside the ASCII set, or reserved syntax characters like ? or & inside a query parameter, the URL must be converted into a valid ASCII format to prevent transmission errors.

In standard URL encoding, unreserved characters are never encoded. These include uppercase and lowercase letters (A-Z, a-z), decimal digits (0-9), hyphen (-), period (.), underscore (_), and tilde (~).

Spaces are typically encoded as %20. However, in application/x-www-form-urlencoded data (such as submitting an HTML form), spaces are often represented by a plus sign +.

URL encoding is used to safely pass data in a web address (query strings and paths), whereas HTML encoding is used to safely display text on a webpage by escaping characters like < and > to prevent Cross-Site Scripting (XSS).

Yes, but you must be careful. If you encode an entire URL using a strict component encoder, the protocol (http://) and path slashes (/) will break. You should use a "Safe URI" mode which preserves these structural characters while encoding the rest.