We are aware that currently the client-side custom validation styles and tooltips are not
accessible, since they are not exposed to assistive technologies. While we work on a solution, we’d
recommend either using the server-side option or the default browser validation method.
How it works
Here’s how form validation works with Bootstrap:
HTML form validation is applied via CSS’s two pseudo-classes, :invalid and
:valid. It applies to <input>, <select>, and
<textarea> elements.
Bootstrap scopes the :invalid and :valid styles to parent
.was-validated class, usually applied to the <form>. Otherwise, any
required field without a value shows up as invalid on page load. This way, you may choose when to
activate them (typically after form submission is attempted).
To reset the appearance of the form (for instance, in the case of dynamic form submissions using
Ajax), remove the .was-validated class from the <form> again after
submission.
As a fallback, .is-invalid and .is-valid classes may be used instead of
the pseudo-classes for server-side validation . They do not require a
.was-validated parent class.
Due to constraints in how CSS works, we cannot (at present) apply styles to a
<label> that comes before a form control in the DOM without the help of custom
JavaScript.
All modern browsers support the
constraint validation API , a series of JavaScript methods for validating form controls.
Feedback messages may utilize the browser defaults (different for
each browser, and unstylable via CSS) or our custom feedback styles with additional HTML and CSS.
You may provide custom validity messages with setCustomValidity in JavaScript.
With that in mind, consider the following demos for our custom form validation styles, optional
server-side classes, and browser defaults.
Custom styles
For custom Bootstrap form validation messages, you’ll need to add the novalidate boolean
attribute to your <form>. This disables the browser default feedback tooltips, but
still provides access to the form validation APIs in JavaScript. Try to submit the form below; our
JavaScript will intercept the submit button and relay feedback to you. When attempting to submit,
you’ll see the :invalid and :valid styles applied to your form controls.
Custom feedback styles apply custom colors, borders, focus styles, and background icons to better
communicate feedback. Background icons for <select>s are only available with
.form-select, and not .form-control.
<form class="row g-3 needs-validation" novalidate>
<div class="col-12">
<label for="validationCustom01" class="form-label">First name</label>
<input type="text" class="form-control" id="validationCustom01" value="Mark" required>
<div class="valid-feedback">
Looks good!
</div>
</div>
<div class="col-12">
<label for="validationCustom02" class="form-label">Last name</label>
<input type="text" class="form-control" id="validationCustom02" value="Otto" required>
<div class="valid-feedback">
Looks good!
</div>
</div>
<div class="col-12">
<label for="validationCustomUsername" class="form-label">Username</label>
<div class="input-group has-validation">
<span class="input-group-text" id="inputGroupPrepend">@</span>
<input type="text" class="form-control" id="validationCustomUsername" aria-describedby="inputGroupPrepend" required>
<div class="invalid-feedback">
Please choose a username.
</div>
</div>
</div>
<div class="col-12">
<label for="validationCustom03" class="form-label">City</label>
<input type="text" class="form-control" id="validationCustom03" required>
<div class="invalid-feedback">
Please provide a valid city.
</div>
</div>
<div class="col-12">
<label for="validationCustom04" class="form-label">State</label>
<select class="form-select" id="validationCustom04" required>
<option selected disabled value="">Choose...</option>
<option value="CA">California</option>
<option value="TX">Texas</option>
<option value="NY">New York</option>
<option value="FL">Florida</option>
<option value="IL">Illinois</option>
<option value="PA">Pennsylvania</option>
<option value="OH">Ohio</option>
<option value="GA">Georgia</option>
<option value="NC">North Carolina</option>
<option value="MI">Michigan</option>
</select>
<div class="invalid-feedback">
Please select a valid state.
</div>
</div>
<div class="col-12">
<label for="validationCustom05" class="form-label">Zip</label>
<input type="text" class="form-control" id="validationCustom05" required>
<div class="invalid-feedback">
Please provide a valid zip.
</div>
</div>
<div class="col-12">
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="invalidCheck" required>
<label class="form-check-label" for="invalidCheck">
Agree to terms and conditions
</label>
<div class="invalid-feedback">
You must agree before submitting.
</div>
</div>
</div>
<!-- Submit Button -->
<div class="col-12">
<button class="btn btn-primary" type="submit">Submit form</button>
</div>
</form>
<form class="row g-3 needs-validation" novalidate> <div
class="col-12"> <label for="validationCustom01"
class="form-label">First name</label> <input type="text"
class="form-control" id="validationCustom01" value="Mark"
required> <div class="valid-feedback"> Looks good! </div> </div>
<div class="col-12"> <label for="validationCustom02"
class="form-label">Last name</label> <input type="text"
class="form-control" id="validationCustom02" value="Otto"
required> <div class="valid-feedback"> Looks good! </div> </div>
<div class="col-12"> <label for="validationCustomUsername"
class="form-label">Username</label> <div class="input-group
has-validation"> <span class="input-group-text"
id="inputGroupPrepend">@</span> <input type="text"
class="form-control" id="validationCustomUsername"
aria-describedby="inputGroupPrepend" required> <div
class="invalid-feedback"> Please choose a username. </div> </div>
</div> <div class="col-12"> <label for="validationCustom03"
class="form-label">City</label> <input type="text"
class="form-control" id="validationCustom03" required> <div
class="invalid-feedback"> Please provide a valid city. </div> </div>
<div class="col-12"> <label for="validationCustom04"
class="form-label">State</label> <select class="form-select"
id="validationCustom04" required> <option selected disabled
value="">Choose...</option> <option
value="CA">California</option> <option
value="TX">Texas</option> <option value="NY">New
York</option> <option value="FL">Florida</option> <option
value="IL">Illinois</option> <option
value="PA">Pennsylvania</option> <option
value="OH">Ohio</option> <option
value="GA">Georgia</option> <option value="NC">North
Carolina</option> <option value="MI">Michigan</option>
</select> <div class="invalid-feedback"> Please select a valid state.
</div> </div> <div class="col-12"> <label
for="validationCustom05" class="form-label">Zip</label> <input
type="text" class="form-control" id="validationCustom05"
required> <div class="invalid-feedback"> Please provide a valid zip.
</div> </div> <div class="col-12"> <div
class="form-check"> <input class="form-check-input"
type="checkbox" value="" id="invalidCheck" required> <label
class="form-check-label" for="invalidCheck"> Agree to terms and
conditions </label> <div class="invalid-feedback"> You must agree before
submitting. </div> </div> </div> <!-- Submit Button --> <div
class="col-12"> <button class="btn btn-primary"
type="submit">Submit form</button> </div> </form>
(() => {
'use strict';
// Fetch all the forms we want to apply custom Bootstrap validation styles to
const forms = document.querySelectorAll('.needs-validation');
// Loop over them and prevent submission
Array.from(forms).forEach((form) => {
form.addEventListener(
'submit',
(event) => {
if (!form.checkValidity()) {
event.preventDefault();
event.stopPropagation();
}
form.classList.add('was-validated');
},
false
);
});
})();
(() => { 'use strict'; // Fetch all the forms we want to apply custom Bootstrap
validation styles to const forms = document.querySelectorAll('.needs-validation'); //
Loop over them and prevent submission Array.from(forms).forEach((form) => {
form.addEventListener( 'submit', (event) => { if (!form.checkValidity()) {
event.preventDefault(); event.stopPropagation(); } form.classList.add('was-validated');
}, false ); }); })();
Browser defaults
Not interested in custom validation feedback messages or writing JavaScript to change form behaviors?
All good, you can use the browser defaults. Try submitting the form below. Depending on your browser
and OS, you’ll see a slightly different style of feedback.
While these feedback styles cannot be styled with CSS, you can still customize the feedback text
through JavaScript.
<form class="row g-3">
<div class="col-12">
<label for="validationDefault01" class="form-label">First name</label>
<input type="text" class="form-control" id="validationDefault01" value="Mark" required>
</div>
<div class="col-12">
<label for="validationDefault02" class="form-label">Last name</label>
<input type="text" class="form-control" id="validationDefault02" value="Otto" required>
</div>
<div class="col-12">
<label for="validationDefaultUsername" class="form-label">Username</label>
<div class="input-group">
<span class="input-group-text" id="inputGroupPrepend2">@</span>
<input type="text" class="form-control" id="validationDefaultUsername" aria-describedby="inputGroupPrepend2" required>
</div>
</div>
<div class="col-12">
<label for="validationDefault03" class="form-label">City</label>
<input type="text" class="form-control" id="validationDefault03" required>
</div>
<div class="col-12">
<label for="validationDefault04" class="form-label">State</label>
<select class="form-select" id="validationDefault04" required>
<option selected disabled value="">Choose...</option>
<option>...</option>
</select>
</div>
<div class="col-12">
<label for="validationDefault05" class="form-label">Zip</label>
<input type="text" class="form-control" id="validationDefault05" required>
</div>
<div class="col-12">
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="invalidCheck2" required>
<label class="form-check-label" for="invalidCheck2">
Agree to terms and conditions
</label>
</div>
</div>
<div class="col-12">
<button class="btn btn-primary" type="submit">Submit form</button>
</div>
</form>
<form class="row g-3"> <div class="col-12"> <label
for="validationDefault01" class="form-label">First name</label>
<input type="text" class="form-control"
id="validationDefault01" value="Mark" required> </div> <div
class="col-12"> <label for="validationDefault02"
class="form-label">Last name</label> <input type="text"
class="form-control" id="validationDefault02" value="Otto"
required> </div> <div class="col-12"> <label
for="validationDefaultUsername" class="form-label">Username</label>
<div class="input-group"> <span class="input-group-text"
id="inputGroupPrepend2">@</span> <input type="text"
class="form-control" id="validationDefaultUsername"
aria-describedby="inputGroupPrepend2" required> </div> </div> <div
class="col-12"> <label for="validationDefault03"
class="form-label">City</label> <input type="text"
class="form-control" id="validationDefault03" required> </div>
<div class="col-12"> <label for="validationDefault04"
class="form-label">State</label> <select class="form-select"
id="validationDefault04" required> <option selected disabled
value="">Choose...</option> <option>...</option> </select>
</div> <div class="col-12"> <label for="validationDefault05"
class="form-label">Zip</label> <input type="text"
class="form-control" id="validationDefault05" required> </div>
<div class="col-12"> <div class="form-check"> <input
class="form-check-input" type="checkbox" value=""
id="invalidCheck2" required> <label class="form-check-label"
for="invalidCheck2"> Agree to terms and conditions </label> </div>
</div> <div class="col-12"> <button class="btn btn-primary"
type="submit">Submit form</button> </div> </form>
Server-side
We recommend using client-side validation, but in case you require server-side validation, you can
indicate invalid and valid form fields with .is-invalid and .is-valid. Note
that .invalid-feedback is also supported with these classes.
For invalid fields, ensure that the invalid feedback/error message is associated with the relevant
form field using aria-describedby (noting that this attribute allows more than one
id to be referenced, in case the field already points to additional form text).
To fix issues with border radius , input
groups require an additional .has-validation class.
<form class="row g-3">
<div class="col-12">
<label for="validationServer01" class="form-label">First name</label>
<input type="text" class="form-control is-valid" id="validationServer01" value="Mark" required>
<div class="valid-feedback">
Looks good!
</div>
</div>
<div class="col-12">
<label for="validationServer02" class="form-label">Last name</label>
<input type="text" class="form-control is-valid" id="validationServer02" value="Otto" required>
<div class="valid-feedback">
Looks good!
</div>
</div>
<div class="col-12">
<label for="validationServerUsername" class="form-label">Username</label>
<div class="input-group has-validation">
<span class="input-group-text" id="inputGroupPrepend3">@</span>
<input type="text" class="form-control is-invalid" id="validationServerUsername" aria-describedby="inputGroupPrepend3 validationServerUsernameFeedback" required>
<div id="validationServerUsernameFeedback" class="invalid-feedback">
Please choose a username.
</div>
</div>
</div>
<div class="col-12">
<label for="validationServer03" class="form-label">City</label>
<input type="text" class="form-control is-invalid" id="validationServer03" aria-describedby="validationServer03Feedback" required>
<div id="validationServer03Feedback" class="invalid-feedback">
Please provide a valid city.
</div>
</div>
<div class="col-12">
<label for="validationServer04" class="form-label">State</label>
<select class="form-select is-invalid" id="validationServer04" aria-describedby="validationServer04Feedback" required>
<option selected disabled value="">Choose...</option>
<option>...</option>
</select>
<div id="validationServer04Feedback" class="invalid-feedback">
Please select a valid state.
</div>
</div>
<div class="col-12">
<label for="validationServer05" class="form-label">Zip</label>
<input type="text" class="form-control is-invalid" id="validationServer05" aria-describedby="validationServer05Feedback" required>
<div id="validationServer05Feedback" class="invalid-feedback">
Please provide a valid zip.
</div>
</div>
<div class="col-12">
<div class="form-check">
<input class="form-check-input is-invalid" type="checkbox" value="" id="invalidCheck3" aria-describedby="invalidCheck3Feedback" required>
<label class="form-check-label" for="invalidCheck3">
Agree to terms and conditions
</label>
<div id="invalidCheck3Feedback" class="invalid-feedback">
You must agree before submitting.
</div>
</div>
</div>
<div class="col-12">
<button class="btn btn-primary" type="submit">Submit form</button>
</div>
</form>
<form class="row g-3"> <div class="col-12"> <label
for="validationServer01" class="form-label">First name</label>
<input type="text" class="form-control is-valid"
id="validationServer01" value="Mark" required> <div
class="valid-feedback"> Looks good! </div> </div> <div
class="col-12"> <label for="validationServer02"
class="form-label">Last name</label> <input type="text"
class="form-control is-valid" id="validationServer02" value="Otto"
required> <div class="valid-feedback"> Looks good! </div> </div>
<div class="col-12"> <label for="validationServerUsername"
class="form-label">Username</label> <div class="input-group
has-validation"> <span class="input-group-text"
id="inputGroupPrepend3">@</span> <input type="text"
class="form-control is-invalid" id="validationServerUsername"
aria-describedby="inputGroupPrepend3 validationServerUsernameFeedback" required>
<div id="validationServerUsernameFeedback" class="invalid-feedback">
Please choose a username. </div> </div> </div> <div
class="col-12"> <label for="validationServer03"
class="form-label">City</label> <input type="text"
class="form-control is-invalid" id="validationServer03"
aria-describedby="validationServer03Feedback" required> <div
id="validationServer03Feedback" class="invalid-feedback"> Please provide
a valid city. </div> </div> <div class="col-12"> <label
for="validationServer04" class="form-label">State</label>
<select class="form-select is-invalid" id="validationServer04"
aria-describedby="validationServer04Feedback" required> <option selected
disabled value="">Choose...</option> <option>...</option>
</select> <div id="validationServer04Feedback"
class="invalid-feedback"> Please select a valid state. </div> </div>
<div class="col-12"> <label for="validationServer05"
class="form-label">Zip</label> <input type="text"
class="form-control is-invalid" id="validationServer05"
aria-describedby="validationServer05Feedback" required> <div
id="validationServer05Feedback" class="invalid-feedback"> Please provide
a valid zip. </div> </div> <div class="col-12"> <div
class="form-check"> <input class="form-check-input is-invalid"
type="checkbox" value="" id="invalidCheck3"
aria-describedby="invalidCheck3Feedback" required> <label
class="form-check-label" for="invalidCheck3"> Agree to terms and
conditions </label> <div id="invalidCheck3Feedback"
class="invalid-feedback"> You must agree before submitting. </div>
</div> </div> <div class="col-12"> <button class="btn
btn-primary" type="submit">Submit form</button> </div>
</form>
Supported elements
Validation styles are available for the following form controls and components:
<input>s and <textarea>s with
.form-control (including up to one .form-control in input groups)
<select>s with .form-select
.form-checks
<form class="was-validated">
<div class="mb-3">
<label for="validationTextarea" class="form-label">Textarea</label>
<textarea class="form-control" id="validationTextarea" placeholder="Required example textarea" required></textarea>
<div class="invalid-feedback">
Please enter a message in the textarea.
</div>
</div>
<div class="form-check mb-3">
<input type="checkbox" class="form-check-input" id="validationFormCheck1" required>
<label class="form-check-label" for="validationFormCheck1">Check this checkbox</label>
<div class="invalid-feedback">Example invalid feedback text</div>
</div>
<div class="form-check">
<input type="radio" class="form-check-input" id="validationFormCheck2" name="radio-stacked" required>
<label class="form-check-label" for="validationFormCheck2">Toggle this radio</label>
</div>
<div class="form-check mb-3">
<input type="radio" class="form-check-input" id="validationFormCheck3" name="radio-stacked" required>
<label class="form-check-label" for="validationFormCheck3">Or toggle this other radio</label>
<div class="invalid-feedback">More example invalid feedback text</div>
</div>
<div class="mb-3">
<select class="form-select" required aria-label="select example">
<option value="">Open this select menu</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>
<div class="invalid-feedback">Example invalid select feedback</div>
</div>
<div class="mb-3">
<input type="file" class="form-control" aria-label="file example" required>
<div class="invalid-feedback">Example invalid form file feedback</div>
</div>
<div class="mb-3">
<button class="btn btn-primary" type="submit" disabled>Submit form</button>
</div>
</form>
<form class="was-validated"> <div class="mb-3"> <label
for="validationTextarea" class="form-label">Textarea</label>
<textarea class="form-control" id="validationTextarea"
placeholder="Required example textarea" required></textarea> <div
class="invalid-feedback"> Please enter a message in the textarea. </div>
</div> <div class="form-check mb-3"> <input type="checkbox"
class="form-check-input" id="validationFormCheck1" required> <label
class="form-check-label" for="validationFormCheck1">Check this
checkbox</label> <div class="invalid-feedback">Example invalid feedback
text</div> </div> <div class="form-check"> <input
type="radio" class="form-check-input" id="validationFormCheck2"
name="radio-stacked" required> <label class="form-check-label"
for="validationFormCheck2">Toggle this radio</label> </div> <div
class="form-check mb-3"> <input type="radio"
class="form-check-input" id="validationFormCheck3"
name="radio-stacked" required> <label class="form-check-label"
for="validationFormCheck3">Or toggle this other radio</label> <div
class="invalid-feedback">More example invalid feedback text</div>
</div> <div class="mb-3"> <select class="form-select"
required aria-label="select example"> <option value="">Open this
select menu</option> <option value="1">One</option> <option
value="2">Two</option> <option value="3">Three</option>
</select> <div class="invalid-feedback">Example invalid select
feedback</div> </div> <div class="mb-3"> <input
type="file" class="form-control" aria-label="file example"
required> <div class="invalid-feedback">Example invalid form file
feedback</div> </div> <div class="mb-3"> <button class="btn
btn-primary" type="submit" disabled>Submit form</button> </div>
</form>
If your form layout allows it, you can swap the .{valid|invalid}-feedback classes for
.{valid|invalid}-tooltip classes to display validation feedback in a styled tooltip. Be
sure to have a parent with position: relative on it for tooltip positioning. In the
example below, our column classes have this already, but your project may require an alternative
setup.
State
Choose...
...
Please select a valid state.
Submit form
<form class="row g-3 needs-validation" novalidate>
<div class="col-md-4 position-relative">
<label for="validationTooltip01" class="form-label">First name</label>
<input type="text" class="form-control" id="validationTooltip01" value="Mark" required>
<div class="valid-tooltip">
Looks good!
</div>
</div>
<div class="col-md-4 position-relative">
<label for="validationTooltip02" class="form-label">Last name</label>
<input type="text" class="form-control" id="validationTooltip02" value="Otto" required>
<div class="valid-tooltip">
Looks good!
</div>
</div>
<div class="col-md-4 position-relative">
<label for="validationTooltipUsername" class="form-label">Username</label>
<div class="input-group has-validation">
<span class="input-group-text" id="validationTooltipUsernamePrepend">@</span>
<input type="text" class="form-control" id="validationTooltipUsername" aria-describedby="validationTooltipUsernamePrepend" required>
<div class="invalid-tooltip">
Please choose a unique and valid username.
</div>
</div>
</div>
<div class="col-md-6 position-relative">
<label for="validationTooltip03" class="form-label">City</label>
<input type="text" class="form-control" id="validationTooltip03" required>
<div class="invalid-tooltip">
Please provide a valid city.
</div>
</div>
<div class="col-md-3 position-relative">
<label for="validationTooltip04" class="form-label">State</label>
<select class="form-select" id="validationTooltip04" required>
<option selected disabled value="">Choose...</option>
<option>...</option>
</select>
<div class="invalid-tooltip">
Please select a valid state.
</div>
</div>
<div class="col-md-3 position-relative">
<label for="validationTooltip05" class="form-label">Zip</label>
<input type="text" class="form-control" id="validationTooltip05" required>
<div class="invalid-tooltip">
Please provide a valid zip.
</div>
</div>
<div class="col-12">
<button class="btn btn-primary" type="submit">Submit form</button>
</div>
</form>
<form class="row g-3 needs-validation" novalidate> <div class="col-md-4
position-relative"> <label for="validationTooltip01"
class="form-label">First name</label> <input type="text"
class="form-control" id="validationTooltip01" value="Mark"
required> <div class="valid-tooltip"> Looks good! </div> </div>
<div class="col-md-4 position-relative"> <label
for="validationTooltip02" class="form-label">Last name</label>
<input type="text" class="form-control"
id="validationTooltip02" value="Otto" required> <div
class="valid-tooltip"> Looks good! </div> </div> <div
class="col-md-4 position-relative"> <label
for="validationTooltipUsername" class="form-label">Username</label>
<div class="input-group has-validation"> <span
class="input-group-text"
id="validationTooltipUsernamePrepend">@</span> <input
type="text" class="form-control" id="validationTooltipUsername"
aria-describedby="validationTooltipUsernamePrepend" required> <div
class="invalid-tooltip"> Please choose a unique and valid username. </div>
</div> </div> <div class="col-md-6 position-relative"> <label
for="validationTooltip03" class="form-label">City</label> <input
type="text" class="form-control" id="validationTooltip03"
required> <div class="invalid-tooltip"> Please provide a valid city.
</div> </div> <div class="col-md-3 position-relative"> <label
for="validationTooltip04" class="form-label">State</label>
<select class="form-select" id="validationTooltip04" required>
<option selected disabled value="">Choose...</option>
<option>...</option> </select> <div class="invalid-tooltip">
Please select a valid state. </div> </div> <div class="col-md-3
position-relative"> <label for="validationTooltip05"
class="form-label">Zip</label> <input type="text"
class="form-control" id="validationTooltip05" required> <div
class="invalid-tooltip"> Please provide a valid zip. </div> </div>
<div class="col-12"> <button class="btn btn-primary"
type="submit">Submit form</button> </div> </form>
// Applies Bootstrap's custom validation styles by preventing form submission if invalid
// and adding the 'was-validated' class to trigger tooltip feedback
(() => {
'use strict';
// Fetch all forms to apply validation styles
const forms = document.querySelectorAll('.needs-validation');
Array.from(forms).forEach(form => {
form.addEventListener('submit', event => {
if (!form.checkValidity()) {
event.preventDefault(); // Prevent submission if form is invalid
event.stopPropagation();
}
form.classList.add('was-validated'); // Add Bootstrap's validation class
}, false);
});
})();
// Applies Bootstrap's custom validation styles by preventing form submission if invalid //
and adding the 'was-validated' class to trigger tooltip feedback (() => { 'use
strict'; // Fetch all forms to apply validation styles const forms =
document.querySelectorAll('.needs-validation'); Array.from(forms).forEach(form => {
form.addEventListener('submit', event => { if (!form.checkValidity()) {
event.preventDefault(); // Prevent submission if form is invalid event.stopPropagation(); }
form.classList.add('was-validated'); // Add Bootstrap's validation class }, false);
}); })();