Alerts
Alerts draw a user’s attention to a change in the status of a form or page. Form-level alerts reflect a user or system action and appear below the form title. Field-level alerts appear inline with input fields and can highlight successful submissions, errors that need to be corrected, or details to know before submitting a form.
Form-level alerts
Information
The information alert is the base alert type without any modifiers. If your alert message requires further explanation, include that content in a paragraph following the main message.
You can also add an explanation to the alert.
This is the explanation of the alert.
HTML code snippet
<div class="m-notification
m-notification--visible">
<div class="m-notification__content">
<div class="m-notification__message">Information alert</div>
</div>
</div>
<br>
<div class="m-notification
m-notification--visible">
<div class="m-notification__content">
<div class="m-notification__message">Information alert</div>
<p class="m-notification__explanation">
You can also add an explanation to the alert.
</p>
</div>
</div>
<br>
<div class="m-notification
m-notification--visible">
<div class="m-notification__content">
<div class="m-notification__message">Information alert</div>
<p class="m-notification__explanation">
This is the explanation of the alert.
</p>
<ul class="m-list m-list--links">
<li class="m-list__item">
<a class="m-list__link" href="/">
This is a link below the explanation
</a>
</li>
<li class="m-list__item">
<a class="m-list__link" href="/">
This is an external link
</a>
</li>
</ul>
</div>
</div>Implementation details
Alerts are hidden by default; you can toggle their visibility by adding or removing the m-notification--visible class to the base element.
Success
The success alert displays when an operation has run as expected, such as returning the number of results in a search.
This is an optional explanation of the success message.
HTML code snippet
<div class="m-notification
m-notification--visible
m-notification--success">
<div class="m-notification__content">
<div class="m-notification__message">11 results</div>
<p class="m-notification__explanation">
This is an optional explanation of the success message.
</p>
<ul class="m-list m-list--links">
<li class="m-list__item">
<a class="m-list__link" href="/">
This is an external link
</a>
</li>
</ul>
</div>
</div>Warning
The warning alert displays when an operation has run as expected, but doesn’t have the expected results, such as a search that returned no result. This alert can also be used to display additional critical information to a user before they submit a form, such as how their data will be used and protected or a reminder that they can’t edit their responses after submitting.
This is an optional explanation of the warning.
HTML code snippet
<div class="m-notification
m-notification--visible
m-notification--warning">
<div class="m-notification__content">
<div class="m-notification__message">No results found.</div>
<p class="m-notification__explanation">
This is an optional explanation of the warning.
</p>
<ul class="m-list m-list--links">
<li class="m-list__item">
<a class="m-list__link" href="/">
This is an external link
</a>
</li>
</ul>
</div>
</div>Error
The error alert displays when an operation has not run as expected and encounters an error. Use after validating on the server side to call out input errors preventing form submission.
This is an optional explanation of the error.
HTML code snippet
<div class="m-notification
m-notification--visible
m-notification--error">
<div class="m-notification__content">
<div class="m-notification__message">Page not found.</div>
<p class="m-notification__explanation">
This is an optional explanation of the error.
</p>
<ul class="m-list m-list--links">
<li class="m-list__item">
<a class="m-list__link" href="/">
This is an external link
</a>
</li>
</ul>
</div>
</div>Implementation details
- For screen reader accessibility, include anchor links to the fields that need correction.
- Place form-level alerts below the form title.
- For field level alerts, the error icon and message should always appear below the input field.
In-progress
The in-progress alert displays when something is happening on the page, such as a page loading as search results are found. Use animated icons to reassure the user that an action is functioning as intended.
HTML code snippet
<div class="m-notification
m-notification--visible">
<div class="m-notification__content">
<div class="m-notification__message">The page is loading…</div>
</div>
</div>Field-level alerts
Field-level alerts reflect validation status and include success, warning, and error. Field-level alerts (icon and message) should always appear below the input field.
Success
HTML code snippet
<div class="m-form-field m-form-field__success">
<input class="a-text-input a-text-input--success" type="text" placeholder="Input text" id="form-input-success" aria-describedby="form-input-success_message">
<div class="a-form-alert a-form-alert--success" id="form-input-success_message" role="alert">
<span class="a-form-alert__text">
This is a field-level alert with a success status.
</span>
</div>
</div>Warning
HTML code snippet
<div class="m-form-field m-form-field__warning">
<input class="a-text-input a-text-input--warning" type="text" placeholder="Input text" id="form-input-warning" aria-describedby="form-input-warning_message">
<div class="a-form-alert a-form-alert--warning" id="form-input-warning_message" role="alert">
<span class="a-form-alert__text">
This is a field-level alert with a warning status.
</span>
</div>
</div>Error
HTML code snippet
<div class="m-form-field m-form-field__error">
<input class="a-text-input a-text-input--error" type="text" placeholder="Input text" id="form-input-error" aria-describedby="form-input-error_message"><div class="a-form-alert a-form-alert--error" id="form-input-error_message" role="alert">
<span class="a-form-alert__text">
This is a field-level alert with an error status.
</span>
</div>Behavior
Placement
- Form-level alerts should appear below the form title.
- Field-level alerts (icon and validation status message) should always appear below the input field.
Validation
Where possible, display formatting errors immediately using client-side validation so the user doesn’t have to wait until submitting to see what went wrong (this is especially frustrating if the information the user enters the first time around is not cached on submit and they have to fill out all the fields again from scratch). If letters are entered in a date field, if an email address is missing the “@” sign, let the user know right away by showing a field-level error on blur.
That said, it’s a good idea to always validate on the server side even if you use client-side validation for formatting checks. That’s because JavaScript validation may not work on all clients; JavaScript errors could occur no matter the client; and JS validation can easily be bypassed, which raises security concerns.
In general, the best practice for server-side validation is to mark errors with both form-level and field-level errors.
Accessibility
- For screen reader accessibility, form-level errors should include anchor links to the problem field in question.
- Place form-level alerts below the form title.
- In general, use distinct icons, contrasting colors, prominent placement, and text to indicate errors. Don’t rely on just one method, as users can have many different accessibility needs (color blind users, visually impaired users, users with motor control issues, etc.).