Alt text is a short description attached to an image, chart, icon, or shape so screen readers can explain it. It also helps exported PDFs and web versions keep the document accessible.
Does this affect you?
Use this for Word for Microsoft 365, Word 2021, Word 2019, Word for Mac, and Word Online when Accessibility Checker reports missing alt text or a document must meet school, work, or accessibility requirements.
Add alt text to one image
The same basic process works for pictures, icons, charts, SmartArt, and many shapes.
- Right-click the image, or select it and open the Picture Format tab.
- Choose View Alt Text, Edit Alt Text, or Format Picture > Alt Text depending on your Word version.
- Review any automatic description Word created. Do not assume it is accurate.
- Type a short description that explains what the image means in this document.
- Close the pane. Word keeps the text automatically.
A useful description explains purpose, not every pixel. For example, Sales chart showing Q3 revenue up 20 percent is more helpful than chart image.
Check the whole document for missing alt text
Use Accessibility Checker instead of hunting manually through a long file.
- Open the Review tab and choose Check Accessibility. Some versions place this under File > Info > Check for Issues.
- Look for Missing Alt Text under errors or warnings.
- Click an item in the checker to jump to that object.
- Add alt text with the same process above.
- Continue until the warnings clear.
More control
Mark decorative images correctly
If an image is only a divider, flourish, or background shape, mark it as decorative in the Alt Text pane. A screen reader can then skip it instead of announcing an unhelpful image.
Keep descriptions concise
One sentence is usually enough. Skip phrases like image of or picture of because screen readers already identify the object type.
Exported files keep the alt text
Alt text added in Word stays attached when saving as PDF or some web formats, which is why it is worth adding before conversion.
Sources
- Microsoft Support – Add alternative text to a shape, picture, chart, SmartArt graphic, or other object (2025)
- Microsoft Support – Rules for the Accessibility Checker (2025)
- Microsoft Support – Everything you need to know to write effective alt text (2024)