Bootstrap 4 supports extraordinary ways to validate your form using the charismatic Tooltips. It also supports both .valid and .invalid feedback as well. For custom validation, you'll need to include novalidate attribute in your form like below, <form class="needs-validation" novalidate > </form> The .valid-tooltip class is used to display the valid feedback message. For invalid feedback message, you'll simply have to include .invalid-tooltip class. Lets see an example, <div class="container"> <h3> <a href="https://primestudyhub.blogspot.com/search/label/Bootstrap%204" target="_blank">BOOTSTRAP 4 FORM VALIDATION - ADVANCED</a></h3> <a href="https://primestudyhub.blogspot.com/search/label/Bootstrap%204" target="_blank">Learn More</a> <form class="needs-validation" novalidate> <div class="form-row"> <div class=...