URL Encoder & Decoder

Encode URL special characters or decode URL-encoded strings.

Share this tool:

Deep Dive: URL Encoding Standards (RFC 3986)

URL encoding, officially known as Percent-encoding, is a method to encode arbitrary data in a Uniform Resource Identifier (URI) using only the limited US-ASCII characters legal within a URI. This is defined in RFC 3986.

Reserved vs. Unreserved Characters

Characters allowed in a URI are either reserved or unreserved. Reserved characters (like /, ?, :, @) have special meaning. If you need to use these characters as data (e.g., a password containing a ?), they must be encoded to avoid confusion with the URL structure.

Security Implications

Proper URL encoding is critical for web security. It helps prevent Cross-Site Scripting (XSS) attacks by ensuring that malicious scripts injected into URL parameters are treated as data rather than executable code.

Frequently Asked Questions

Why are there "%20" signs in my URL?

The %20 represents a space character. Since spaces are not allowed in URLs, they are replaced by the % symbol followed by the ASCII hexadecimal code for space (20).

What is the difference between URI and URL encoding?

Technically, all URLs are URIs, so the terms are often used interchangeably. However, JavaScript provides two functions: encodeURI() (which preserves special protocol characters like ://) and encodeURIComponent() (which encodes everything, including / and :). This tool uses the latter for maximum safety.

Is it safe to decode unknown URLs?

Yes, decoding a URL simply reveals the underlying text. However, always be cautious before visiting a decoded URL if you don't recognize the domain, as it could be a phishing link.

Was this tool helpful?

Comments

Loading comments...