Screen readers and other assistive technologies cannot translate non-text content. Adding alternative text to define
<object> elements helps assistive technologies convey meaning to users.
How this Lighthouse audit fails #
<object> elements that don't have alternative text:
The Lighthouse Accessibility score is a weighted average of all the accessibility audits. See the Lighthouse accessibility scoring post for more information.
How to add alternative text to
<object> elements #
Describe the object in the text content of the
<object> element. In the example below
2019 Web Accessibility Report is the description of the object.
2019 Web Accessibility Report
Learn more in Include text alternatives for images and objects.
You can also use
alt and ARIA labels to describe object elements, for example,
<object type="application/pdf" data="/report.pdf alt="2019 Web Accessibility Report">. (See <object> elements must have alternate text.)
Tips for writing effective
alt text #
- As previously mentioned, describe the information contained in the embedded object.
- Alternative text should give the intent, purpose, and meaning of the object.
- Blind users should get as much information from alternative text as a sighted user gets from the object.
- Avoid non-specific words like "chart", "image", or "diagram".
Learn more in WebAIM's guide to Alternative Text.