required
The required boolean attribute forces a form control to have a value before the form can be submitted.
Syntax
requiredExamples
<input type="email" name="email" required>
<button type="submit">Sign up</button>
Output
Blocks submission and shows a native validation message if the email field is empty or invalid.
Notes
A boolean attribute that triggers the :required pseudo-class and constraint validation. Pair with a visible label and an accessible error message; do not rely on the native bubble alone.
Browser & runtime support
| Environment | Since version |
|---|---|
| chrome | 5.0 |
| firefox | 4.0 |
| safari | 10.1 |
| edge | 12 |