URL Encode / Decode

URL Encode / Decode — Percent Encoding Explained

URL encoding (also called percent-encoding) is a mechanism for encoding information in a Uniform Resource Identifier (URI). URLs can only be transmitted over the Internet using the ASCII character set. Characters outside this set — like spaces, special characters, and non-Latin letters — must be converted into a format that can be transmitted safely.

How URL Encoding Works

Each character that needs encoding is represented as a percent sign (%) followed by two hexadecimal digits. For example:

• Space → %20 (or + in form data)
• @ → %40
• / → %2F
• ? → %3F
• = → %3D
• & → %26
• Hindi/Arabic/Non-ASCII characters → multi-byte percent sequences

When Do You Need URL Encoding?

• Query strings: When passing data in URLs like ?name=John+Doe&city=New+York
• Form submission: HTML forms encode data before submission (application/x-www-form-urlencoded)
• API development: Encoding parameters when building API request URLs programmatically
• Multilingual URLs: Encoding non-ASCII characters for internationalized URLs

urlencode vs. rawurlencode

urlencode converts spaces to + and is used for form data. rawurlencode (RFC 3986) converts spaces to %20 and is the standard for URL paths and query strings. When in doubt, use rawurlencode for URLs.