How do I add custom validation messages to a Bootstrap input group while maintaining form layout?
Asked on Nov 13, 2025
Answer
To add custom validation messages to a Bootstrap input group while maintaining the form layout, you can use Bootstrap's validation classes along with custom JavaScript to display your messages.
<!-- BEGIN COPY / PASTE -->
<form class="needs-validation" novalidate>
<div class="input-group mb-3">
<input type="text" class="form-control" id="customInput" required>
<div class="invalid-feedback">
Please provide a valid input.
</div>
</div>
<button class="btn btn-primary" type="submit">Submit</button>
</form>
<script>
// JavaScript for disabling form submissions if there are invalid fields
(function () {
'use strict';
var forms = document.querySelectorAll('.needs-validation');
Array.prototype.slice.call(forms).forEach(function (form) {
form.addEventListener('submit', function (event) {
if (!form.checkValidity()) {
event.preventDefault();
event.stopPropagation();
}
form.classList.add('was-validated');
}, false);
});
})();
</script>
<!-- END COPY / PASTE -->Additional Comment:
✅ Answered with Bootstrap 5 best practices.- The `needs-validation` class is used to enable Bootstrap's custom validation styles.
- The `novalidate` attribute is added to prevent the browser's default validation.
- The `invalid-feedback` div provides the custom validation message.
- JavaScript is used to handle the form submission and apply the `was-validated` class to trigger validation styles.
- Ensure your input has the `required` attribute or other validation constraints as needed.
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