URL Encoder / Decoder

What is URL Encoding?

URL encoding (also known as percent-encoding) is a mechanism for converting characters in a Uniform Resource Locator (URL) into a format that can be safely transmitted over the internet. Reserved characters and non-ASCII characters are replaced with a % followed by two hexadecimal digits.

How URL Encoding Works

Characters that are not allowed in a URL — such as spaces, quotation marks, angle brackets, and non-ASCII characters — are converted to their percent-encoded equivalents. For example, a space becomes %20, and the ampersand & becomes %26. The unreserved characters (A–Z a–z 0–9 - _ . ~) are never encoded.

Common Use Cases

URL encoding is essential when passing query parameters that contain special characters, building OAuth or API URLs, encoding redirects, and constructing mailto links with subject lines. It is defined by RFC 3986.