Write alt text that explains an image’s purpose

Before you start

Use Word or PowerPoint with an image you are allowed to share. Microsoft’s AI alt-text feature can draft a description; you decide whether it communicates the image’s purpose. The companion guide explains how to request a draft.

A worked example

Imagine a column chart showing support requests dropping from 40 in April to 25 in May. The surrounding paragraph discusses that decrease.

Weak description: “A blue and green chart.” The colours do not explain the result.

Useful description: “Support requests fell from 40 in April to 25 in May.” If the same information is already given in nearby accessible text, avoid repeating it unnecessarily.

Review the description

1. Read the paragraph or slide title beside the image.
2. Identify what the image adds.
3. Check every name, number and claim in the draft.
4. Replace vague object lists with the relevant information.
5. Remove details that do not help the reader.
6. Mark a purely decorative image as decorative.

If AI cannot describe it accurately

Write the description yourself. For a complex chart or diagram, put the detailed explanation in ordinary document text and use alt text to identify the image. Do not expect one generated sentence to communicate all relationships.

Availability and limits

The example is fictional and the review checklist is editorial advice. Microsoft warns that generated descriptions can be inaccurate. Do not infer people’s identities, emotions or sensitive characteristics from an image.

Sources and checks

• Microsoft: AI-generated alt text

Documentation checked: 2026-10-10. Product steps have not been tested in a signed-in vendor app for this edition.

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