PowerPoint Automatic Alt Text Generation: How to Improve Quality

PowerPoint can automatically generate alt text for images you insert into your slides. This feature uses Microsoft 365 cloud-based image analysis to describe the content of a picture. However, the generated descriptions are often too generic, incomplete, or simply wrong. This article explains how the automatic alt text system works, shows you how to edit and improve the generated descriptions, and provides steps to disable the feature if you prefer to write your own alt text from scratch.

How PowerPoint Automatic Alt Text Generation Works

PowerPoint uses a cloud-based Microsoft 365 service that applies computer vision algorithms to analyze images. The service detects objects, people, text, and scene categories. It then generates a short sentence describing the image. The algorithm is not perfect. It can misidentify objects, miss important context, or produce descriptions that are too vague for screen reader users.

The feature is enabled by default in PowerPoint for Microsoft 365 and PowerPoint 2021. It works on JPEG, PNG, GIF, BMP, and TIFF images. The generated alt text is stored in the image metadata and is read aloud by screen readers such as Narrator, JAWS, and NVDA. If you do not edit the generated text, your audience may hear descriptions like “A picture containing text, screenshot, person, indoor” instead of a meaningful description.

Steps to Review and Improve Automatic Alt Text

Follow these steps to review the alt text PowerPoint generated and replace it with a better description.

1. Select the image
   Click the image on your slide. The Picture Format tab appears on the ribbon.
2. Open the Alt Text pane
   Right-click the image and select Edit Alt Text. The Alt Text pane opens on the right side of the window.
3. Review the generated description
   The pane shows a text box labeled “Alt text.” If PowerPoint generated text, you will see a sentence like “A close-up of a person holding a phone.” Read it carefully. Does it describe the image accurately? Does it include the key details a blind user needs?
4. Edit the alt text
   Click inside the text box and replace the generated text with your own description. Use complete sentences. Include the subject, action, and any text visible in the image. For example: “A woman in a red jacket holds a smartphone showing a map of downtown Seattle.”
5. Mark the image as decorative if needed
   If the image is purely decorative and adds no information, check the box “Mark as decorative.” Screen readers will then skip the image entirely.
6. Close the Alt Text pane
   Click the X in the upper-right corner of the pane. Your changes are saved automatically.

How to Disable Automatic Alt Text Generation

If you prefer to write all alt text manually, turn off the automatic generation feature.

1. Open PowerPoint Options
   Click File > Options.
2. Go to Ease of Access
   In the left panel, click Ease of Access.
3. Uncheck automatic alt text
   Under the Automatic Alt Text section, uncheck the box labeled “Automatically generate alt text for me.”
4. Click OK
   Click OK to save the setting. PowerPoint will no longer generate alt text for new images you insert.

What to Do When the Generated Alt Text Is Wrong

The automatic alt text feature can produce descriptions that are misleading or nonsensical. Common failures include misidentifying people, objects, and text. Here are three specific scenarios and how to fix them.

“A picture containing text, screenshot, person, indoor” — Generic Descriptions

This is the most common complaint. PowerPoint often lists tags instead of writing a sentence. Replace the tags with a concise sentence. For example: “Screenshot of the PowerPoint ribbon showing the Insert tab with the Pictures button highlighted.”

“A person smiling at the camera” — Missing Context

The algorithm may detect a face but miss the setting or activity. Edit the text to add context: “A presenter stands in front of a whiteboard with a flowchart drawn on it.”

“A close-up of a product” — No Brand or Text

If the image contains a logo or label, the algorithm rarely reads the text. Manually include the brand name and any visible words: “The Microsoft Surface Laptop 5 on a wooden desk with the Windows 11 desktop visible on the screen.”

Best Practices for Writing Alt Text in PowerPoint

Follow these guidelines to create alt text that is helpful for screen reader users.

• Be concise but descriptive. Use one to two sentences. Do not exceed 125 characters if possible.
• Start with the subject. Example: “A man in a blue shirt sits at a desk typing on a laptop.”
• Include text that appears in the image. If the image is a chart, describe the data type and trend. If it is a screenshot, describe what is shown.
• Do not use phrases like “image of” or “picture of.” Screen readers announce the element type automatically.
• Use proper punctuation. Capitalize the first word and end with a period.
• For complex images such as charts or diagrams, provide a longer description. Use the Alt Text pane to write a detailed paragraph or provide a separate text summary on the slide.

Automatic Alt Text vs Manual Alt Text: Key Differences

Item	Automatic Alt Text	Manual Alt Text
Quality	Often generic or incorrect	Accurate and context-aware
Time required	Instant but needs editing	Takes 30–60 seconds per image
Control	Cannot control what is generated	Full control over wording
Best for	Decorative or simple images	Complex images, charts, screenshots
Screen reader output	May confuse users	Clear and useful

Automatic alt text can save time, but it should never be trusted without review. The best approach is to use automatic generation as a starting point and then edit the text to match your specific content and audience. For important presentations where accessibility is required, always write manual alt text.