Accessible Slides (Microsoft PowerPoint & Google Slides)

Built-in layouts already contain accessible structure: correctly ordered placeholders, consistent formatting, and enough contrast for most audiences. Custom text boxes, shapes used as text containers, or manually arranged elements often break reading order for screen readers.

Do:

• Start with a built-in layout and modifywithinit.

• Use PowerPoint’s accessible templates when possible.

A person with a visual disability that uses a screen reader relies on the slide titles to know which slide is which. So, each slide should have a unique and descriptive title.

When sighted people looks at a slide, they read it based on the layout/placement(usually top-to-bottom), screen readers read based onhistory(the order in which items were created). This creates a conflict: if you add the slide’s title last, a screen reader will read it last; even if it visually sits at the very top of the page, which can confuse the listener. Use the Selection Pane toset the order in which screen readers read the slide contents. 

• Select Home > Arrange > Selection Pane.

• Arrange the Items: A list of all your slide elements (images, text boxes, titles) will appear in a side panel. You can drag and drop these items to change their order.

• The Critical Rule: "Bottom-Up" Logic: This part is the most important because it is counter-intuitive:The list is upside down. The screen reader starts reading at the Bottom of the list. It finishes reading at the Top of the list. So, you should add your Title(the first thing you want heard) to the very bottom of the list. Drag the item you want heard last to the very top. 

Readable slides help everyone, especially learners with low vision, dyslexia, or cognitive processing differences.

Best practices:

• Use large, sans-serif fonts (at least 18 points for body text and 20 points or larger for headings and titles.)

• Maintain strong color contrast (dark text on a light background or vice versa).

• Avoid all caps and dense paragraphs.

• Don’t rely on color alone to convey meaning.

While images are powerful tools for communication, they are meaningless to visually impaired users without description. Lacking this context creates a frustrating and exclusionary experience. Alternative text (alt text) provides a brief description of a visual (including photos, shapes, charts, and embedded objects, etc.) and is essential for users relying on screen readers. It should describe the visual's content or function, or indicate if the image is decorative. Screen readers will read this description aloud, allowing non-visual users to access the same information. Avoid relying on images that contain important text. If text must appear inside an image, make sure that same text also appears in the body of the document. Check out theMicrosoft Support guide on writing effective alt text

Right-click on the image and select the Alt Text option in the dropdown menu. This will open a window where you can enter a description of the image or mark the image as decorative. If the image is purely decorative, check the “Mark as decorative” box.

Using Google Gemini to Generate Alt Text

Writing effective alt text—especially for figures, charts, graphs, and equations—can be time-consuming. Google Gemini streamline this process by generating a strong first draft for you to review.

Important: To protect sensitive data, always sign in with your UC Berkeley (CalNet) account to use campus-licensed AI tools. This ensures your content is not used to train external models.

Step-by-Step Workflow

1. Open Gemini: Sign in to your bConnected suite. Select the Google Apps grid (upper-right) and launch Gemini. 
2. Capture the Image: In your document (Acrobat, Word, or PowerPoint), use a screen-capture tool (Mac: Shift-Command-4; Windows: Win+Shift+S) to copy the image to your clipboard. 
3. Generate Alt Text: Paste the image into the Gemini prompt area and type: "Provide concise alt text for this image". Press Enter.
4. Review and Transfer: Verify the output for accuracy and instructional relevance. Click the Copy response icon and paste the text into the alt text field of your application

Bulk Alt Text Workflow with Gemini

Instead of capturing individual screenshots, you can analyze an entire document at once to generate a full list of alt text descriptions.

1. Prepare Your File

• Slides/Docs: Save your file as a PDF first. (e.g., File > Download > PDF Document). This ensures Gemini sees charts and layouts correctly.

2. Upload to Gemini

• Open Gemini and ensure you are logged in with your CalNet account.

• Click the + (Upload) button and select your PDF file.

3. Copy and paste the following into the chat:

"Analyze the attached file and create a table listing every image and stock photo found (do not group them). Create a table with these columns:

• Page Number

• Visual Reference (e.g., 'Bar chart on left')

• Alt Text (Provide a concise sentence describing the image's core meaning or data trend)."

4. Review and Apply

Gemini will generate a table. Verify the descriptions for accuracy, then copy/paste the text from the table directly into the Alt Text field of your original document.

Important Note: While this workflow can save enormous amounts of time, it is a starting point, not a perfect solution. AI may occasionally skip complex images or misinterpret context. Always review the generated text to ensure it is accurate and matches your instructional intent.

1. Managing Complex Diagrams 

STEM slides often use diagrams–arrows, separate labels, and shapes. A screen reader will try to read every single arrow and box individually, which is confusing. The Solution: Grouping. You want the screen reader to treat the diagram asone single object.

• Method A: Grouping Logic

  1. Select all arrows, shapes, and labels.

  2. Right-click→Group→Group.

  3. Add Alt Text to theentire Group.

  4. Crucial step: Ensure the individual items inside the group are marked as decorative.

• Method B: Flatten to Image

  1. Select all components.

  2. Right-click→Save as Picture.

  3. Delete the original loose components and drag your new "flatter" image back onto the slide.

  4. Add Alt Text to this single new image.

2. Math Notations & LaTeX

Screenshots of equations are invisible to screen readers.The Fix:

1. Keep your visual equation (screenshot or image) on the slide for sighted students.

2. Mark that image as Decorative.

3. Create a separate Text Boxon the slide.

4. Type the equation in LaTeX format inside this text box.

5. Move this text box off-screen or hide it behind the image (check reading order).

   • Why? Students with visual impairments often use tools that can parse LaTeX code into readable math.

3. Flowcharts & Graphs (Mermaid)

Flowcharts describe processes. Instead of writing a long paragraph describing the flow, consider using Mermaid Markdown:

1. Write the diagram structure using Mermaid syntax (a text-based way to represent charts).

2. Paste this code into the Alt Text or a hidden text box.

3. This allows the student to "read" the structure rather than trying to interpret a vague visual description. Mermaid uses simple text symbols (like arrows) to show relationships. A blind student reading this code hears the logic immediately:

   Start --> Is_Password_Correct?Is_Password_Correct? -- Yes --> WelcomeIs_Password_Correct? -- No --> Retry

   By providing the Mermaid text, you aren't describing shapes (diamonds, squares); you are describing the logic of the workflow, which is what the student actually needs to know.

Screen readers rely on a strict reading order. If your slide reveals 3 distinct formulas sequentially:

1. Check Reading Order:Ensure the order in the Selection Pane matches your animation order.

2. Separate Text Boxes:Do not put three different formulas into one text box and animate lines of text inside it. Use three separate text boxes. This ensures the screen reader announces the specific formula exactly when it appears on screen.

Tables in slides are often small, visually dense, and inaccessible on mobile or magnification tools. If you must include a table:

• Use a simple structure (no merged/split cells or nested tables.)

• Add a header row.

• Ensure the table reads logically. Screen readers interpret tables row by row, from left to right, so place information in a logical, left-to-right order that makes sense when read aloud.

• Test on a mobile device to check for unavoidable horizontal scrolling.

Whenever possible, replace tables with:

• bullet lists

• structured text

• simplified visuals

Ensure hyperlinks clearly describe their destination. Use clear, descriptive link text instead of phrases like “click here” or "Go to this page" or full URLs. For example, use “Course Syllabus” to make links easier to understand and navigate, especially for users of screen readers. The exception is email addresses; these should be typed out (e.g., rtl-admin@berkeley.edu, as screen readers may not recognize linked text as an email address.

In PowerPoint, the Accessibility Checker runs automatically in the background when you're creating a presentation. If the Accessibility Checker detects accessibility issues, you will get a reminder in the status bar.

To manually launch the Accessibility Checker, select Review > Check Accessibility. The Accessibility pane opens, and you can now review and fix accessibility issues.

Just like in PowerPoint, Google Slides templates are designed so that the Title is always read first and the Body is read second. When you create a new presentation, Google applies a default theme. You can switch this at any time using the Theme button, and the accessibility features will carry over.

• To add new slides, click the(+)button to add a new slide. This defaults to a standard "Title and Body" format.
• If you need a different look (e.g., two columns or a caption), click the Layout button and select a pre-made template.
• The "Blank Slide" Trap: Avoid selecting the Blank layout. Blank slides have no underlying reading order, meaning any text box you draw manually might be read out of sequence by a screen reader. Always start with a layout that closely matches your needs and modify it from there.

PowerPoint has the "Selection Pane" (a visual list you can reorder). Google Slides does nothave a native list view to check reading order. To check the reading order in Google Slides, click on the Slide 1 thumbnail on the left of the screen and then press the Tab key. Watch the blue focus box jump from object to object.This is the order the screen reader will speak. To change the reading order: 

• Select an object.

• Go to Arrange  → Order

• Use Bring Forward / Send backward to adjust the order in which assistive technologies read items. 

  • To make something read FIRST:Right-click →Order→Send to Back(This puts it "behind" everything else, making it the first item the computer finds)

  • To make something read LAST:Right-click →Order→Bring to Front

This can get messy if your objects overlap visually. If you send your background image to the "Front" to make it read last, it might cover up your text. This is why using built-in layouts is even more critical in Google Slides than in PowerPoint.

UC Berkeley has branded Google Slides templates thatare designed with accessibility standards in mind, and we encourage you to use them. However, using a template doesn't guarantee accessibility if you override its structure. So, make sure that you avoid deleting the standard placeholders(e.g., 'Click to add text') to replace them with your own text boxes, as this breaks the reading order. Instead, simply move the existing boxes to fit your needs.

Slides that contain equations or multi-step diagrams are often harder to make fully accessible in Google Slides. PowerPoint provides stronger tools for managing reading order and describing complex graphics, so it’s the better choice when working with this type of content. See the PowerPoint section above for tips.

Grackle is the accessibility checker Google never built. It's an add-on (Grackle Docs / Slides / Sheets) that scans your file and flags common issues, such as missing or out-of-order headings, improper lists, missing alt text, vague link text, unsupported or unlabeled table headers/structure, basic color/contrast problems, etc. It also provides step-by-step guidance to resolve each issue and. Learn more about Grackle on Berkeley's Digital Accessibility Program (DAP) website(link is external). To use Grackle Slides follow the next steps: 

• Go to Extensions  → Add-ons → Get add-ons → search “Grackle Slides.”

• Install and open via Extensions → Grackle Slides → Launch.

• Let it scan your slide deck for issues such as:

  • Missing titles

  • Poor color contrast

  • Missing alt text

  • Reading order issues