Form Validation

Client-side and server-side validation examples

Required Fields

Mandatory

Email Validation

Format

Password Strength

Security

Password strength: Weak

  • At least 8 characters
  • One uppercase letter
  • One lowercase letter
  • One number

Pattern Matching

Regex

Format: 123-456-7890

5-digit ZIP code

Custom Validation

Rules

Min 4 characters, alphanumeric only

Must be 18 or older

Real-time Validation

Live

Enter 16 digits