Alerts

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.

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.

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:

CSS

Variables

As 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))

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.)

Basic usage:

const alert = bootstrap.Alert.getOrCreateInstance('#myAlert')
alert.close()

Events

Bootstrap’s alert plugin exposes a few events for hooking into alert functionality.

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()
})