URL encoding (also known as percent-encoding) converts characters into a format that can be safely transmitted over the internet. It ensures that URLs remain valid and secure by encoding special characters.
Why URL Encoding is Important:
- Security - Prevents URL injection attacks
- Compatibility - Ensures URLs work across different systems
- Reliability - Prevents broken links from special characters
- Standards Compliance - Follows RFC 3986 standards
Commonly Encoded Characters:
When to Use URL Encoding:
- Query parameters in URLs
- Form data submission
- API requests with special characters
- URLs containing spaces or non-ASCII characters
- Data being passed in HTTP headers
Technical Details:
// JavaScript functions used:
encodeURIComponent(string) - Encodes a URI component
decodeURIComponent(string) - Decodes a URI component
// Example:
encodeURIComponent('hello world') = 'hello%20world'
decodeURIComponent('hello%20world') = 'hello world'
Best Practices:
- Always encode user input before including it in URLs
- Use encodeURIComponent() for query parameters
- Use encodeURI() for complete URLs (preserves ://, etc.)
- Decode URLs before displaying to users
- Validate decoded input for security