How to Add Descriptive Alt Text to Word Images for Accessibility Compliance

Screen readers rely on alt text to describe images for users who are blind or have low vision. Without it, a picture is invisible to assistive technology. Word provides a built-in Alt Text pane where you can add a meaningful description to any image, shape, chart, or SmartArt graphic. This article explains how to write effective alt text and how to add it correctly so your documents meet WCAG 2.1 accessibility standards.

What Alt Text Does and When You Need It

Alt text (alternative text) is a short written description of an image that screen readers speak aloud. It is required for all non-decorative images under the Web Content Accessibility Guidelines (WCAG) 2.1 Level A and AA. Government agencies, educational institutions, and many private organizations now require alt text for compliance with Section 508 of the Rehabilitation Act in the United States and the European Accessibility Act in the EU.

Word automatically generates a suggested alt text for inserted photos using AI. This suggestion is often inaccurate or too generic. You must replace it with a human-written description that matches the image’s purpose in the document.

Images that need alt text include:

• Photographs and illustrations that convey information
• Charts, graphs, and diagrams
• Icons that represent an action or concept
• Logos that identify an organization
• Screenshots showing a specific result

Decorative images — such as borders, dividers, or background patterns — do not need alt text. Instead, you mark them as decorative so screen readers ignore them entirely.

How to Add or Edit Alt Text in Word

You can add alt text to any image, shape, chart, SmartArt, or 3D model. The process is the same for all object types.

1. Right-click the image
   Select Edit Alt Text from the context menu. The Alt Text pane opens on the right side of the Word window.
2. Delete the automatic suggestion
   Word may show a generated description in the text box. Highlight it and press Delete. Do not leave the auto-generated text — it is rarely accurate enough for compliance.
3. Type a concise description
   Write 1 to 2 sentences that describe the image’s content and its purpose in the document. Focus on what the reader needs to know. For example: “Bar chart showing quarterly sales for 2024. Q1: 120,000 units, Q2: 145,000 units, Q3: 132,000 units, Q4: 168,000 units.”
4. Close the Alt Text pane
   Click the X in the top-right corner of the pane. Word saves the alt text automatically.

Marking an Image as Decorative

1. Right-click the image
   Select Edit Alt Text.
2. Check “Mark as decorative”
   In the Alt Text pane, check the box labeled Mark as decorative. The text box becomes grayed out and unavailable.
3. Close the pane
   The image is now hidden from screen readers.

Adding Alt Text to a Chart or SmartArt

1. Select the chart or SmartArt object
   Click the border of the chart or SmartArt graphic to select the entire object, not just one element inside it.
2. Right-click and choose Edit Alt Text
   The Alt Text pane opens.
3. Write a summary of the data or concept
   For charts, include the chart type, the trend, and the key numbers. For SmartArt, describe the relationship between the items — for example: “Flowchart showing the hiring process: application, screening, interview, offer, onboarding.”

Common Mistakes to Avoid When Writing Alt Text

Using “Image of” or “Picture of”

Screen readers already announce that the element is an image. Starting alt text with “Image of” or “Picture of” is redundant and wastes the user’s time. Start directly with the subject: “Woman reading a book on a park bench” not “Image of a woman reading a book on a park bench.”

Leaving the Auto-Generated Text

Word’s AI-generated alt text often describes visible objects but misses the context. For example, it might say “A man in a suit shaking hands with another man” when the image actually shows the CEO signing a merger deal. Replace the auto text with a description that explains the image’s relevance to the document.

Writing Too Much or Too Little

Alt text should be 1 to 3 sentences. If the image is complex — like a full infographic — provide a short summary in the alt text and include a longer description in the document body or in an appendix. Do not copy the entire body text into the alt text field.

Forgetting Alt Text on Linked or Embedded Objects

Images that are copied from another document or pasted from a web browser often lose their alt text. Always verify alt text after pasting. Also check images inside tables, headers, and footers — screen readers can reach those areas, and alt text is needed there too.

Not Testing With a Screen Reader

The best way to confirm alt text works is to test the document with a screen reader such as Narrator (built into Windows) or NVDA (free). Press Windows logo key + Ctrl + Enter to start Narrator, then navigate through the document with the Tab key and arrow keys. If the screen reader skips an image or reads a description that does not match the image, edit the alt text.

Word Online vs Desktop: Alt Text Feature Differences

Item	Word for Desktop	Word for the Web
Add alt text	Yes — right-click > Edit Alt Text	Yes — right-click > Edit Alt Text
Mark as decorative	Yes	Yes
Auto-generated alt text	Yes — AI-generated	No — blank text box
Edit alt text on charts	Yes	No — alt text is read-only for charts
Bulk edit multiple images	No — each image individually	No

Word for the Web does not generate automatic alt text, so you must write every description manually. Chart alt text in Word for the Web is read-only — you must use the desktop version to edit it. For compliance work, use Word for Desktop to ensure full control over all object types.

You can now add accurate alt text to every image in your Word documents and meet WCAG 2.1 accessibility requirements. Start by reviewing your existing documents using the Accessibility Checker in Word — go to Review > Check Accessibility. Use the built-in Alt Text pane to fix flagged images. For advanced compliance, create a company style guide for alt text that includes tone, length, and formatting rules for common image types such as charts and screenshots.