Form Validation Patterns

React 19 forms require validation on both client and server.

Client-Side Validation

Use HTML5 validation + custom logic:

<form action={submitForm}>
  <input
    name="email"
    type="email"
    required
    pattern="[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}$"
  />