Examples
Alerts are available for any length of text, as well as an optional close button. For proper styling, use one of the eight required contextual classes (e.g., .alert-success
). For inline dismissal, use the alerts JavaScript plugin.
alert-variant()
Sass mixin is deprecated. Alert variants now have their CSS variables overridden in the Sass loop.
.visually-hidden
class.
Live example
Click the button below to show an alert (hidden with inline styles to start), then dismiss (and destroy) it with the built-in close button.
We use the following JavaScript to trigger our live alert demo:
const alertPlaceholder = document.getElementById('liveAlertPlaceholder')
const alert = (message, type) => {
const wrapper = document.createElement('div')
wrapper.innerHTML = [
`<div class="alert alert-${type} alert-dismissible" role="alert">`,
` <div>${message}</div>`,
' <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>',
'</div>'
].join('')
alertPlaceholder.append(wrapper)
}
const alertTrigger = document.getElementById('liveAlertBtn')
if (alertTrigger) {
alertTrigger.addEventListener('click', () => {
alert('Nice, you triggered this alert message!', 'success')
})
}
Link color
Use the .alert-link
utility class to quickly provide matching colored links within any alert.
Additional content
Alerts can also contain additional HTML elements like headings, paragraphs and dividers.
Well done!
Aww yeah, you successfully read this important alert message. This example text is going to run a bit longer so that you can see how spacing within an alert works with this kind of content.
Whenever you need to, be sure to use margin utilities to keep things nice and tidy.
Icons
Similarly, you can use flexbox utilities and Bootstrap Icons to create alerts with icons. Depending on your icons and content, you may want to add more utilities or custom styles.
Need more than one icon for your alerts? Consider using more Bootstrap Icons and making a local SVG sprite like so to easily reference the same icons repeatedly.
Dismissing
Using the alert JavaScript plugin, it’s possible to dismiss any alert inline. Here’s how:
- Be sure you’ve loaded the alert plugin, or the compiled Bootstrap JavaScript.
- Add a close button and the
.alert-dismissible
class, which adds extra padding to the right of the alert and positions the close button. - On the close button, add the
data-bs-dismiss="alert"
attribute, which triggers the JavaScript functionality. Be sure to use the<button>
element with it for proper behavior across all devices. - To animate alerts when dismissing them, be sure to add the
.fade
and.show
classes.
You can see this in action with a live demo:
closed.bs.alert
event and programmatically sets focus()
to the most appropriate location in the page. If you’re planning to move focus to a non-interactive element that normally does not receive focus, make sure to add tabindex="-1"
to the element.
CSS
Variables
Added in v5.2.0As part of Bootstrap’s evolving CSS variables approach, alerts now use local CSS variables on .alert
for enhanced real-time customization. Values for the CSS variables are set via Sass, so Sass customization is still supported, too.
--#{$prefix}alert-bg: transparent;
--#{$prefix}alert-padding-x: #{$alert-padding-x};
--#{$prefix}alert-padding-y: #{$alert-padding-y};
--#{$prefix}alert-margin-bottom: #{$alert-margin-bottom};
--#{$prefix}alert-color: inherit;
--#{$prefix}alert-border-color: transparent;
--#{$prefix}alert-border: #{$alert-border-width} solid var(--#{$prefix}alert-border-color);
--#{$prefix}alert-border-radius: #{$alert-border-radius};
--#{$prefix}alert-link-color: inherit;
Sass variables
$alert-padding-y: $spacer;
$alert-padding-x: $spacer;
$alert-margin-bottom: 1rem;
$alert-border-radius: $border-radius;
$alert-link-font-weight: $font-weight-bold;
$alert-border-width: var(--#{$prefix}border-width);
$alert-bg-scale: -80%;
$alert-border-scale: -70%;
$alert-color-scale: 40%;
$alert-dismissible-padding-r: $alert-padding-x * 3; // 3x covers width of x plus default padding on either side
Sass loop
Loop that generates the modifier classes with the alert-variant()
mixin.
// Generate contextual modifier classes for colorizing the alert
@each $state in map-keys($theme-colors) {
.alert-#{$state} {
--#{$prefix}alert-color: var(--#{$prefix}#{$state}-text);
--#{$prefix}alert-bg: var(--#{$prefix}#{$state}-bg-subtle);
--#{$prefix}alert-border-color: var(--#{$prefix}#{$state}-border-subtle);
--#{$prefix}alert-link-color: var(--#{$prefix}#{$state}-text);
}
}
JavaScript behavior
Initialize
Initialize elements as alerts
const alertList = document.querySelectorAll('.alert')
const alerts = [...alertList].map(element => new bootstrap.Alert(element))
info >}}
For the sole purpose of dismissing an alert, it isn’t necessary to initialize the component manually via the JS API. By making use of data-bs-dismiss="alert"
, the component will be initialized automatically and properly dismissed.
See the triggers section for more details.
Triggers
Dismissal can be achieved with the data
attribute on a button within the alert as demonstrated below:
<button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
or on a button outside the alert using the data-bs-target
as demonstrated below:
<button type="button" class="btn-close" data-bs-dismiss="alert" data-bs-target="#my-alert" aria-label="Close"></button>
Note that closing an alert will remove it from the DOM.
Methods
You can create an alert instance with the alert constructor, for example:
const bsAlert = new bootstrap.Alert('#myAlert')
This makes an alert listen for click events on descendant elements which have the data-bs-dismiss="alert"
attribute. (Not necessary when using the data-api’s auto-initialization.)
Method | Description |
---|---|
close |
Closes an alert by removing it from the DOM. If the .fade and .show classes are present on the element, the alert will fade out before it is removed. |
dispose |
Destroys an element’s alert. (Removes stored data on the DOM element) |
getInstance |
Static method which allows you to get the alert instance associated to a DOM element. For example: bootstrap.Alert.getInstance(alert) . |
getOrCreateInstance |
Static method which returns an alert instance associated to a DOM element or create a new one in case it wasn’t initialized. You can use it like this: bootstrap.Alert.getOrCreateInstance(element) . |
Basic usage:
const alert = bootstrap.Alert.getOrCreateInstance('#myAlert')
alert.close()
Events
Bootstrap’s alert plugin exposes a few events for hooking into alert functionality.
Event | Description |
---|---|
close.bs.alert |
Fires immediately when the close instance method is called. |
closed.bs.alert |
Fired when the alert has been closed and CSS transitions have completed. |
const myAlert = document.getElementById('myAlert')
myAlert.addEventListener('closed.bs.alert', event => {
// do something, for instance, explicitly move focus to the most appropriate element,
// so it doesn't get lost/reset to the start of the page
// document.getElementById('...').focus()
})