Power Point Image & Charts (Alt Text)

PowerPoint Accessibility Technical Standard 4: Images & Charts (Alt Text)

The “Why” Behind the Standard

Screen readers can announce that a graphic exists, but they cannot explain what the image represents. Alternative text (alt text) provides that essential context. Without it, students using assistive technology miss the instructional value conveyed by visual content.

The Goal: Provide a clear, concise description of the meaning of an image, or mark the image as decorative if it conveys no instructional information.

Step 1: Access the Alt Text Pane

Modern versions of PowerPoint include a dedicated pane for managing alt text.

1. Right‑click the image, chart, or graphic.
2. Select View Alt Text.
3. The Alt Text pane opens on the right side of the screen.

Step 2: Write Effective Alt Text

The quality of the description is just as important as its presence.

• Be concise: Aim for one or two sentences. Screen‑reader users do not need lengthy, overly detailed descriptions for simple visuals.
• Focus on intent: Describe why the image is included, not its colors or visual details.
• Avoid redundancy: Do not begin with phrases like “Image of” or “Picture of.” Screen readers already announce that the item is a graphic.

• Bad: “A picture of a dog.”
• Good: “A Golden Retriever acting as a service animal for a person using a wheelchair.”

Step 3: Handle Decorative Images

If an image is purely decorative—such as visual flourishes, background shapes, or non‑instructional stock photos—it should not be read by a screen reader.

1. Open the Alt Text pane.
2. Select Mark as decorative.
3. Result: The screen reader skips the image entirely, keeping the user focused on meaningful content.

Step 4: Manage Complex Charts and Graphs

Charts often contain more data than can reasonably fit into standard alt text. Use one of the following professional approaches:

• Option A — Summary: Use alt text to summarize the key finding or trend (for example, “Bar chart showing graduation rates increased by 15% from 2020 to 2024”).
• Option B — Data Table: Provide the raw data in an accessible table on the following slide and use alt text to direct the user to that table.

Step 5: Use Caution with Auto‑Generated Alt Text

PowerPoint may offer to automatically generate alt text.

• The Problem: Automated descriptions are often inaccurate or lack instructional context.
• The Rule: You may use auto‑generated text as a starting point, but you must review and edit it to meet instructional and accessibility standards.

Step 6: Validation

1. Go to Review and select Check Accessibility.
2. Address any errors labeled “Missing alternative text.”
3. Selecting an item in the Accessibility Pane will take you directly to the image that needs attention.

Quick Checklist for Alt Text

• [ ] Do all instructional images have concise, meaningful descriptions?
• [ ] Are purely decorative images marked as Decorative?
• [ ] For charts, did I describe the trend or finding rather than the visuals?
• [ ] Did I avoid starting descriptions with “Image of” or “Picture of”?