Nobody likes submitting a form only to get an error page. HTML5 has built-in client-side validation that catches common mistakes before the data leaves the browser — no JavaScript needed!

The required Attribute

Add required to any input to make it mandatory:

<input type="text" name="name" required>

If a user tries to submit without filling in a required field, the browser will show an error message automatically.

Input Types with Built-In Validation

Some input types validate format automatically:

Min and Max Length

<input type="text" name="username" minlength="3" maxlength="20" required>

The browser will not let users type more than 20 characters, and will show an error if they type fewer than 3.

The placeholder vs required Distinction

• placeholder shows hint text — it is not a substitute for a label.


• required enforces that the field must be filled — it is validation.

Your Task

Create a registration form with:

Each input must have a <label>.