URL Encode & Decode
Encode or decode URL components — component or full URL mode.
What is URL Encoding (Percent-Encoding)?
How to Use This Tool
Characters That Must Be Encoded
Frequently Asked Questions
- What is URL encoding?
- URL encoding (percent-encoding) converts special characters into a format that can be transmitted in URLs. Characters like spaces, &, =, and non-ASCII characters are replaced with a % sign followed by their hexadecimal value.
- What is the difference between component and full URL encoding?
- Component encoding (encodeURIComponent) encodes everything except letters, digits, and - _ . ~ — use this for query parameter values. Full URL encoding (encodeURI) preserves URL structure characters like :, /, ?, #, and & — use this for complete URLs.
- Why do spaces become %20 or +?
- In URLs, spaces are encoded as %20 (RFC 3986 standard). In HTML form data (application/x-www-form-urlencoded), spaces become +. Both represent a space, but %20 is the correct encoding for URL paths and query parameters.
- Is my data sent to a server?
- No. All encoding and decoding happens in your browser using JavaScript. Your data stays on your device.
- When should I URL-encode data?
- Always encode user input before putting it in URLs — query parameters, path segments, and fragment identifiers. This prevents broken URLs and protects against injection attacks.