URL encoding (also called percent-encoding) converts special characters into a format that can be safely transmitted in a URL. Each character is replaced with a "%" followed by its two-digit hexadecimal representation — for example, a space becomes %20 and "&" becomes %26. This is necessary because URLs can only contain a limited set of ASCII characters.

encodeURI is designed for full URLs — it encodes most special characters but leaves the ones that have structural meaning in a URL intact (like :// ? & = # /). encodeURIComponent is meant for individual query parameter values — it encodes everything except letters, digits, and - _ . ! ~ * ' ( ). Use encodeURIComponent when encoding a value that will appear inside a query string.

The ASCII code for a space character is 32, which is 0x20 in hexadecimal. Percent-encoding simply takes the hexadecimal byte value of a character and prefixes it with "%". Some older systems encode spaces as "+" (used in HTML form submissions), but the modern standard is %20.

You need to encode a URL whenever it contains characters that are not allowed in a URL or that have a special meaning you want to suppress. Common situations include: passing a URL as a query parameter, building dynamic links in JavaScript, writing API requests programmatically, or embedding special characters like spaces, ampersands, or hash signs in query string values.

Yes — that is exactly what Encode Component is for. For example, if you want to pass an email address as a query value, use encodeURIComponent("user@example.com") to get user%40example.com. Always encode individual values with encodeURIComponent, not the entire URL.