PURPOSE Alt text describes meaningful images for people who cannot see them or when images do not load. WHAT TO DESCRIBE Describe the purpose or information the image communicates, not every visual detail. WHEN ALT TEXT CAN BE EMPTY Decorative images that add no meaning may not need descriptive alt text. CHARTS AND DIAGRAMS Summarize the key takeaway and provide detailed data nearby if needed. BEST PRACTICE Ask: what would someone miss if this image disappeared?