Validating Form Inputs

To validate form inputs in HTML, you can use built-in attributes like required, minlength, and type="email" to ensure users enter the correct information before the form is submitted.

HTML5 comes with a powerful set of validation features that work directly in the browser without needing any JavaScript. These are quite handy for providing instant feedback to your visitors and reducing the number of errors sent to your server.

Basic Validation Attributes

The most common way to enforce validation is by adding a few key attributes to your input tags. Here are the main ones:

• required: Prevents the form from being submitted if the field is empty.
• minlength and maxlength: Sets a limit on the number of characters allowed in a text field.
• min and max: Used for number and date inputs to define a range of acceptable values.

Example:

Automatic Type Validation

When you use specific input types like email or url, the browser will automatically check if the user's entry matches that format. If it doesn't, the browser will prevent submission and show an error message:

Full Working Example

The following example uses various validation techniques to create a secure signup form: