Alt Text
Alternative (alt) text is required for all images where supported. Alt text should should describe the essential content and function of the image. Read the accessibility foundations to learn the basics of writing effective alt text.
Some features (Instagram Stories, LinkedIn multi-image posts) don’t allow alt text. When alt text fields aren't available, write descriptive image details in the post copy itself. Also consider creating an accessible companion post or webpage with full image descriptions, and link to that.
In Canva and other tools: Use built-in alt text checkers. AI tools may help draft alt text, but always review for clarity and accuracy.
Color Contrast
All text/images must meet at least a 4.5:1 contrast ratio. Use UMB’s Color Contrast Checker or other tools such as the Vispero Color Contrast Analyzer or Canva’s built-in contrast checker. Add solid color backgrounds behind text overlays. Repeat key text in the caption if contrast can’t be fixed.
QR Codes
Avoid using QR codes. They have a low click-through rate and aren’t great for accessibility. Screen readers cannot “scan” a QR code embedded in an image. Additionally, most people consume social on mobile phones, and not all can long press on a QR code to open it.
If you must use a QR code, provide a text alternative. For example, “Scan the QR code or visit umaryland.edu/events to register.” Add the destination link directly in the post caption. Use branded, shortened URLs in addition to QR codes so that screen reader users have another way to access the resource. Avoid using shortened URLs with random characters in the address, such has bit.ly/xbdg12d3. See more guidance on the use of links on social media.
In alt text, describe the QR code’s function, not just “QR code.” For example, “QR code linking to UMB’s Fall 2025 Open House registration page.”
Think of QR codes as supplemental, not the only path to information.
Recommended Font Sizes
Because social platforms automatically resize graphics for mobile devices, text that qualifies as “large” in graphic design software (such as Canva) often appears much smaller to users. As a result, UMB does not rely on the WCAG “large text” contrast exception for social media.
Minimum font size: 24 points
For readability on mobile devices, UMB recommends 32 points or larger for key information such as dates, times, and locations.
Why 24 Points?
- Social platforms downscale images significantly.
- 18 point (WCAG “large text”) becomes visually small on phones.
- 24 point in graphic design software (such as Canva) typically renders as the barely acceptable minimum on mobile.