Form Validation
5 min read
Add required, minlength, maxlength, min, max, and pattern attributes for built-in HTML5 validation. The browser blocks submission and shows error messages. Style inputs with :valid and :invalid CSS pseudo-classes.
HTML5 Form Validation
<input type="text" required minlength="2" maxlength="50">
<input type="email" required>
<input type="number" min="18" max="120">
<input type="text" pattern="[A-Za-z0-9]{6,12}" title="6-12 alphanumeric chars">
<input type="url">
<!-- Disable built-in validation (for custom JS) -->
<form novalidate>