URL Encoder / Decoder

What Is It?

The URL Encoder / Decoder converts special characters in URLs to their percent-encoded equivalents and back. Percent-encoding (also called URL encoding) replaces unsafe ASCII characters with a % followed by two hexadecimal digits.

This tool works entirely in your browser — no data is uploaded to any server.

How to Use

1. Select Encode or Decode mode using the toggle buttons.
2. Paste your URL or text into the input field.
3. The conversion happens automatically as you type.
4. Click Copy to copy the result to your clipboard.

Example

Encoding:

Input: https://example.com/search?q=hello world&lang=en

Output: https%3A%2F%2Fexample.com%2Fsearch%3Fq%3Dhello%20world%26lang%3Den

Decoding:

Input: %7B%22name%22%3A%22Alice%22%7D

Output: {"name":"Alice"}

Benefits

• Instant conversion — encode or decode as you type with no delay.
• Bidirectional — easily switch between encode and decode modes.
• Handles all special characters — spaces, angle brackets, quotes, and more.
• 100% private — your URLs never leave your browser.

Common Use Cases

• Encoding query parameters before embedding in API requests.
• Decoding percent-encoded URLs received in logs or analytics.
• Building properly formatted request strings for REST APIs.
• Escaping special characters in redirect URLs.
• Debugging malformed URLs in web applications.

Technical Deep Dive

URL encoding is defined by RFC 3986. It specifies that certain characters in a URL must be encoded to avoid ambiguity. For example, a space character becomes %20, an ampersand & becomes %26, and a plus + becomes %2B.

This tool uses the browser’s built-in encodeURIComponent() and decodeURIComponent() functions to perform conversions, which faithfully follow the RFC 3986 specification.

Frequently Asked Questions

What is the difference between encodeURI and encodeURIComponent?

encodeURI is designed to encode a complete URL, leaving characters like /, ?, #, and & intact since they are meaningful in a URL. encodeURIComponent encodes everything including these characters, making it better suited for encoding individual query parameter values. Our tool uses encodeURIComponent for maximum compatibility.

Why does a space become %20 and not +?

URL encoding has two standards: RFC 3986 uses %20 for spaces, while application/x-www-form-urlencoded (used in HTML forms) uses +. Our tool follows RFC 3986, using %20. Some tools used for form data use +, which our decoder also handles.

Can I decode a full URL at once?

Yes. Paste the full encoded URL and switch to Decode mode. The tool will decode all %XX sequences back to their original characters.