URL Encode/Decode
Encode or decode URLs and query strings instantly. Free online URL encoder and decoder that runs entirely in your browser.
What is URL Encode/Decode?
URL Encode/Decode is a free online tool that converts special characters in URLs to their percent-encoded equivalents and vice versa. URL encoding (also called percent-encoding) is essential for ensuring that URLs are transmitted correctly, especially when they contain spaces, special characters, or non-ASCII text. Without proper encoding, characters like ampersands, question marks, and spaces can break URL parsing, cause incorrect routing, or introduce security vulnerabilities in web applications.
How to use this URL Encode/Decode tool?
- Choose whether you need to encode (convert special characters to percent codes) or decode (convert percent codes back to readable text).
- To encode, enter your URL or text in the input field and click Encode URL.
- To decode, paste your percent-encoded URL and click Decode URL.
- Review the output to ensure all special characters have been properly encoded or decoded.
- Copy the result from the output field using the Copy button.
Tips & Best Practices
Encode Query Parameters Individually
When building URLs with multiple query parameters, encode each parameter value separately rather than encoding the entire URL. The structural characters like ?, &, and = should remain unencoded so the URL structure is preserved. Only the parameter values need encoding.
Double-Check Decoded URLs Before Clicking
If you receive an encoded URL and want to see where it leads, decode it first to inspect the full destination. This is a good security practice, as malicious links sometimes use URL encoding to disguise phishing domains or harmful query parameters.
Use for Debugging Web Applications
When debugging web applications, URL-encoded parameters in the browser's address bar can be hard to read. Paste the entire URL into the decode field to see all query parameters in plain text, making it much easier to identify issues with parameter values.
Handle Plus Signs Carefully
In URL query strings, the plus sign (+) is sometimes used as an alternative encoding for spaces (instead of %20). This tool uses the standard percent-encoding (%20 for spaces). If you are working with form data that uses plus signs for spaces, be aware of this difference when decoding.
Common Use Cases
Building Dynamic URLs in Code
When constructing URLs programmatically — such as adding user-provided search terms to a query string — you must encode the values to handle spaces and special characters correctly. Use this tool to verify that your encoding logic produces the expected output, or to quickly encode test values when debugging URL construction in your application.
Sharing Links with Special Characters
URLs containing non-English characters (Chinese, Japanese, Arabic, etc.), emojis, or special symbols need proper encoding to work in all contexts — emails, messaging apps, documents, and HTML. Encode the URL before sharing to ensure recipients can click it and arrive at the correct destination regardless of their platform or email client.
Analyzing Web Traffic and Logs
Server access logs and analytics data often contain URL-encoded paths and query parameters. Decode these URLs to understand what pages users visited and what search terms or filter values they used. This is essential for debugging routing issues, analyzing user behavior, and troubleshooting 404 errors.
FAQ
Why do URLs need to be encoded?
URLs can only contain a limited set of ASCII characters. Special characters like spaces, ampersands, and non-ASCII characters must be percent-encoded to be transmitted correctly in web addresses and query strings.
What characters are encoded in URL encoding?
URL encoding converts reserved characters (such as &, =, ?, #, and spaces) and non-ASCII characters into a percent sign followed by their hexadecimal value (e.g., a space becomes %20).
What is the difference between encodeURI and encodeURIComponent?
In JavaScript, encodeURI() encodes a complete URI but preserves structural characters like :, /, ?, and #. encodeURIComponent() encodes everything except alphabetic characters, digits, and a few special characters (- _ . ! ~ * ' ( )). Use encodeURIComponent() for query parameter values and encodeURI() for complete URLs. This tool uses encodeURIComponent behavior for maximum encoding.
Can URL encoding prevent XSS attacks?
URL encoding alone is not sufficient to prevent cross-site scripting (XSS) attacks, but it is an important part of a defense-in-depth strategy. When user input is included in URLs, encoding prevents special characters from being interpreted as HTML or JavaScript. However, proper XSS prevention requires context-specific output encoding, content security policies, and input validation as well.
Why do some URLs contain %20 and others use + for spaces?
Both %20 and + can represent a space in URLs, but they come from different standards. %20 is the standard percent-encoding defined in RFC 3986 and works everywhere in a URL. The plus sign (+) for spaces comes from the application/x-www-form-urlencoded format used in HTML form submissions and only applies within query string values. For maximum compatibility, %20 is the safer choice.