URL encoding (also called percent encoding) converts characters that are not allowed in a URL into a safe format. Each unsafe character is replaced with a % followed by two hexadecimal digits representing the character's UTF-8 byte value. For example, a space becomes %20 and & becomes %26.

The % characters you see in URLs are percent-encoded characters. URLs can only contain a limited set of ASCII characters safely. Any character outside that set — including spaces, non-ASCII letters, and special symbols — must be url encode'd using the %XX format so the URL is transmitted correctly by browsers and servers.

encodeURI is designed for encoding a full URL — it preserves characters like :, /, ?, &, = that have structural meaning in a URL. encodeURIComponent is designed for encoding a single query parameter value — it encodes those structural characters too, so the value cannot be confused for URL structure. Use encodeURIComponent (Component mode) for individual values.

Switch to Decode mode and paste your percent-encoded string. The tool uses the native decodeURIComponent function to decode it instantly in your browser. This converts %20 back to space, %26 back to &, and so on. Your data never leaves your device.

No. URL encoding and Base64 encoding solve different problems. URL encoding replaces unsafe URL characters with %XX sequences and is used to safely transmit data in URLs. Base64 encoding converts binary data to a printable ASCII string and is used for transmitting binary data over text-based protocols. They are not interchangeable.