URL Decoder


Use this online free URL Decoder tool for decoding URLs. Start by typing or pasting a URL encoded string in the input text area above, click the Submit button and the tool will decode your input string.

A URL (Uniform Resource Locator) is a resource address on the world wide web. URLs have a well-defined structure which was formulated in RFC 1738 by Tim Berners-Lee, the inventor of the worldwide web.

URL decoding is the inverse process of URL encoding. It parses query strings or path parameters passed in URLs.

According to RFC 3986, the characters in a URL have to be taken from a defined set of unreserved and reserved ASCII characters. Any other characters are not allowed in a URL.

URL parameter values include ASCII alphanumeric characters easily. Certain characters are “reserved,” and they have to be encoded to make sure that the server interprets the URL correctly. URL encoding should not be done anywhere except in parameter values. Characters are encoded by replacing it with a percent sign (%), followed by the appropriate two-digit hexadecimal string.

URLs only contain a set of characters from the US-ASCII character set including Alphabets (A-Z a-z), Digits (0-9), hyphen (-), underscore (_), tilde (~), and dot (.). Any other character outside this allowed set is encoded using URL encoding or Percent encoding.

How does URL Decoding work?

Here are the rules that are applied for decoding query strings, path parameters, or HTML form parameters:

  1. The alphanumeric characters a - z, A - Z, and 0 - 9 do not change and remain the same.
  2. Safe characters like -, _, ~, and ~ also do not change and remain the same.
  3. Any sequence of the form %xy is treated as a byte where xy is the two-digit hexadecimal representation of the 8 bits. Then, all substrings that contain one or more of these byte sequences consecutively is replaced by the character(s) whose encoding would result in those consecutive bytes.