How can you handle invalid form submissions in HTML?

2 Use JavaScript validation

Another way to handle invalid form submissions in HTML is to use JavaScript validation. This gives you more control and flexibility over the validation logic and the user feedback. You can use the addEventListener method to attach a function to the submit event of the form. In this function, you can use the checkValidity method to check if the form is valid, and the reportValidity method to display the error messages. You can also use the setCustomValidity method to set your own error messages for each input field. If the form is invalid, you can use the preventDefault method to stop the form from being submitted.

3 Use server-side validation

The third way to handle invalid form submissions in HTML is to use server-side validation. This is the most reliable and secure way to validate the user input, as it does not depend on the browser or the JavaScript settings. You can use any server-side language, such as PHP, Ruby, or Python, to process the form data and check for any errors or malicious inputs. You can then send back a response to the user, either by redirecting them to a confirmation or an error page, or by displaying the error messages on the same page using sessions or cookies.

4 Use CSS feedback

The fourth way to handle invalid form submissions in HTML is to use CSS feedback. This is a way to enhance the user experience and the visual design of your forms. You can use the :valid and :invalid pseudo-classes to style your input fields based on their validity state. For example, you can use green and red borders or icons to indicate if the input is valid or invalid. You can also use the :focus pseudo-class to highlight the active input field. You can also use the ::placeholder pseudo-element to show a hint or an example of the expected input.

5 Use accessibility features

The fifth way to handle invalid form submissions in HTML is to use accessibility features. This is a way to make your forms more accessible and user-friendly for people with disabilities or special needs. You can use the label element to associate a text label with each input field, which helps screen readers and keyboard users. You can also use the aria-invalid and aria-describedby attributes to indicate the validity state and the error message of each input field, which helps screen readers and voice assistants. You can also use the tabindex attribute to control the order of the focusable elements in your form, which helps keyboard users.

6 Use user testing

The sixth way to handle invalid form submissions in HTML is to use user testing. This is a way to evaluate and improve the usability and effectiveness of your forms. You can use various methods, such as surveys, interviews, observations, or analytics, to collect feedback from your target users. You can then use this feedback to identify and fix any issues or problems with your forms, such as unclear instructions, confusing labels, or unexpected errors. You can also use this feedback to optimize and enhance your forms, such as adding help texts, tooltips, or autocomplete features.