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Alerts give feedback to users, provide critical information, and/or offer key supplementary details about a task.


Informational (Default)












React Properties Documentation
alertRef(...args: any[]) => any

Access a reference to the alert div element


Analytics events tracking is enabled by default. Set this value to false to disable tracking for this component instance.


An override for the dynamic content sent to analytics services. By default this content comes from the heading.

In cases where this component’s heading may contain sensitive information, use this prop to override what is sent to analytics.


Sets the focus on Alert during the first mount


The alert's body content


Text for the alert heading


Optional id used to link the aria-labelledby attribute to the heading. If not provided, a unique id will be automatically generated and used.

headingLevel'1' | '2' | '3' | '4' | '5' | '6''2'

Heading type to override default <h2>.


Boolean to hide the Alert icon

role'alert' | 'alertdialog' | 'region' | 'status''region'

ARIA role, defaults to 'region'


A string corresponding to the Alert weight classes (lightweight)

variation'error' | 'warn' | 'success'

A string corresponding to the Alert variation classes (error, warn, success)


The following Sass variables can be overridden to customize Alert components:

Sass variables for alert
VariableDefault Core Theme Value

Google Analytics

Analytics event tracking is disabled by default.

Enable event tracking

Import and set the setAlertSendsAnalytics feature flag to true in your application's entry file:

import { setAlertSendsAnalytics } from '@cmsgov/<design-system-package>';

On applications where the page has utag loaded, the data goes to Tealium which allows it to route to Google Analytics or the currently approved data analytics tools.

Disable event tracking

For the analytics prop, pass the value false to the component to disable analytics tracking for a singular component instance


Override event tracking

A custom heading value can be sent for an analytics event by using the prop analyticsLabelOverride. It is recommended that this value be used to prevent sensitive personal information from being passed to analytics trackers.



  • Don’t overdo it — too many notifications will either overwhelm or annoy the user and are likely to be ignored.
  • Write the message in concise, human readable language; avoid jargon and computer code.
  • Don’t include notifications that aren’t related to the user’s current goal.
  • When the user is required to do something in response to an alert, let them know what they need to do and make that task as easy as possible.
  • Be mindful of other elements on the page that may compete for the user’s attention.

When to use

  • As a validation message that alerts someone that they just did something that needs to be corrected or as confirmation that a task was completed successfully.
  • As a callout or notification for important or timely information. This includes errors, warnings, and general information.
  • Drawing focus to an error or an incomplete task by prompting the user to review or take other action.
  • Confirming the successful competition of a task.
  • Providing key supplementary or contextual information to support the successful completion of tasks or aid overall comprehension.

When to consider alternatives

  • On long forms, always include in-line validation in addition to any error messages that appear at the top of the form. When possible, simplify forms by rewriting and where possible, splitting long forms across multiple pages
  • If an action will result in destroying a user’s work (for example, deleting an application) use a more intrusive pattern, such as a confirmation modal dialogue, to allow the user to confirm that this is what they want.
  • When you need to display content that isn't related to the user’s current goal.

When the alert is for an error:

  • Be polite in error messages — don’t place blame on the user.
  • Users generally won’t read documentation but will read a message that helps them resolve an error; include some educational material in your error message.
  • If the error relates to specific text fields, give these fields an error state as well.


  • Use the ARIA role="alert" to inform assistive technologies of a time-sensitive and important message that is not interactive. If the message is interactive, use the role="alertdialog" instead.
  • Consider putting the alert inside a div with aria-live="polite" and aria-relevant="additions removals". These ARIA attributes ensure screen readers will announce alerts that have been added or updated dynamically.
  • If you choose to shift focus to the Alert, be mindful that using other techniques like role="alert", and aria-live="polite" will cause some browser and screen reader combinations to read out the content more than once. Typically, shifting focus alone will be enough to alert screen readers of the content.
  • Do not visually hide alert messages on the page and then make them visible when they are needed. Users of older assistive technologies may still be able to perceive the alert messages even if they are not currently applicable.
  • Alerts should give users adequate time to review and comprehend the provided information. Avoid hiding alerts using a timer.
  • Include a mechanism like a button to dismiss alerts where appropriate.

Learn more