HTML URL Encoding Reference

URL Encoding (Percent Encoding)

A URL (web address) can only contain a small set of characters: letters (A-Z and a-z), numbers (0-9), and a few symbols like !, *, ', (, ), -, _, ., and ~.

URL encoding turns any other character into a safe code the URL can carry. Each such character becomes a % sign followed by two hexadecimal digits. A space, for example, becomes %20.

URL encoding is also called percent-encoding, because of the % sign.

Why is it Needed?

1. Some characters are not allowed. Spaces and letters like æ, ø, or å cannot go straight into a URL.

2. Some characters have special jobs. In a URL:

• ? starts a query string
• & seperates values
• = connects a name to a value
• # points to a spot on the page

If your data contains one of these, the browser will misread it.

Browsers encode URLs automatically when you type them or submit a form.

In JavaScript, you can do it yourself, with the encodeURIComponent() function.

Click the "URL Encode" button to see how the JavaScript function encodes the text.

URL Encoding Reference

Your browser will encode input, according to the character-set used in your page. The default character-set in HTML5 is UTF-8.