URL Encoder / Decoder

What is URL Encoding?

URL encoding, also known as percent-encoding, is the process of converting characters that are not allowed or have special meaning in a URL into a safe representation using a percent sign followed by two hexadecimal digits. For example, a space becomes %20, an ampersand becomes %26, and an equals sign becomes%3D. This is necessary because URLs can only contain a limited set of characters from the ASCII character set — letters, digits, hyphens, underscores, periods, and tildes are safe, but everything else must be encoded. Without proper encoding, browsers and servers may misinterpret characters like & or= as query-string delimiters rather than literal values. This tool supports bothencodeURIComponent, which encodes individual parameter values, and encodeURI, which encodes a full URL while preserving structural characters like colons, slashes, and question marks. Decoding reverses the process, restoring percent-encoded strings back to their original readable form.

How to Use This Tool

1. Select the mode: click Encode to convert plain text into a URL-safe format, or Decode to convert a percent-encoded string back to readable text.
2. Choose the encoding type from the dropdown: URI Component encodes everything including colons and slashes (best for query parameter values), while Full URI preserves URL structure characters.
3. Paste or type your text into the input panel on the left.
4. Click the Encode URL or Decode URL button to process your input.
5. The result appears in the output panel on the right. Click Copy to send it to your clipboard.

Tips and Best Practices

• Use encodeURIComponent (URI Component mode) when encoding values that will be placed inside query string parameters — this encodes characters like &, =, and / that would otherwise break the URL structure.
• Use encodeURI (Full URI mode) only when encoding a complete URL where you want to preserve the protocol, domain, path separators, and query delimiters.
• Double-encoding is a common mistake. If your text already contains percent-encoded sequences like %20, decoding first and then re-encoding prevents sequences like %2520.
• When building URLs programmatically, always encode user-supplied input to prevent injection attacks and malformed requests.
• Test decoded output carefully — if decoding produces an error, the input may contain an invalid percent sequence such as %ZZ, which is not valid hexadecimal.
• Remember that the plus sign (+) is sometimes used to represent a space in form submissions but is not the same as %20. This tool uses standard percent-encoding, which converts spaces to %20.