Make your course accessible — meet requirements and improve the learning experience for all students. Get started quickly with tools, guides, and support.
Start with Ally in Canvas
Ally is the main tool we use to help identify and improve accessibility issues in Canvas course content. Ally scans files and course materials, gives accessibility scores, and provides step-by-step guidance for fixing common issues.
Use Ally to:
- Find accessibility issues in course files and Canvas content
- Improve documents, images, PDFs, and presentations
- Add image descriptions and identify decorative images
- Provide students with alternative formats when available
Go to: Ally for Instructors
Common Accessibility Fixes
Use the guides below to address the most common accessibility issues in online courses:
- Add image descriptions
- Fix PDFs
- Improve PowerPoint accessibility
- Caption course videos
- Check Canvas content for accessibility
Add Image Descriptions
Images need short, meaningful descriptions so all students can understand the content.
How to add image descriptions in Canvas (using Ally)
- Select the accessibility score indicator next to your file or content
- Review the issue for “Missing image description”
- Enter a clear, meaningful description of the image
- Select Add
If the image is only decorative and does not add meaning, mark it as decorative instead.
Write better image descriptions
- Focus on what matters in the image, not every detail
- Be concise
- Include any text shown in the image
- Don’t write “image of” or “picture of”
- Don’t repeat what’s already explained on the page
Example
Too vague: “Chart”
Better: “Bar chart showing enrollment increased from 200 to 450 students between 2020 and 2024”
Fix PDFs
PDFs are one of the most common accessibility issues in online courses. Many PDFs are scanned or poorly formatted, making them difficult or impossible for screen readers to use.
- Avoid uploading scanned PDFs when possible
- Use original source files (Word, PowerPoint) and export as accessible PDFs
- Ensure text is selectable (not an image of text)
- Add headings and proper structure
- Add alt text for any images
Use Ally to help
- Select the accessibility score indicator next to your PDF
- Review the issues flagged by Ally
- Follow the step-by-step guidance to improve the file
When to replace instead of fix
If a PDF is heavily scanned or poorly structured, it’s often faster and more effective to:
- Replace it with a Word document or HTML page
- Recreate the content in Canvas
This improves accessibility and usability for all students.