Complete Guide to URL Encoding & Web Security
Why URL Encoding Matters
- 🔒 Prevent XSS attacks
- 🌐 Support international characters
- 📦 Preserve data integrity
Did You Know?
Space can be encoded as %20 or + depending on context
Encoding Standards
| Character | Encoded | Usage |
|---|---|---|
| Space | %20 | URL paths |
| + | %2B | Query parameters |
| ? | %3F | Query separators |
Security Best Practices
🛡️ Input Validation
- Whitelist allowed characters
- Limit maximum length
🔐 Output Encoding
- Context-aware encoding
- Use proper functions
📚 RFC Compliance
- RFC 3986 (URI)
- RFC 5987 (Charset)
Encoding Checklist
Security Warning: Always validate before decoding!
- Identify components (path/query/fragment)
- Choose proper encoding function
- Handle double-encoding scenarios
- Test with edge cases
- Implement error handling
FAQ: URL Encoding
encodeURI preserves full URL structure while encodeURIComponent encodes all special characters for URL components.