There is no single font size that makes every social media graphic readable. Readability depends on the image width, the size at which it is displayed, the typeface, contrast, and the amount of text. Test the finished graphic at its likely phone display size.
A design can look clear at full size in an editor and become exhausting to read in a feed. Fixing that usually means simplifying the message before increasing the export resolution.
Understand the scaling problem
Imagine a graphic that is 1,080 pixels wide, displayed at 360 pixels wide. Everything in it becomes about one-third of its original size. A 30-pixel letter height becomes roughly 10 display pixels in this simplified example.
Actual apps and devices scale content differently, but the principle holds: the source font-size number does not describe what the reader experiences.
Start with a layout that remains clear at a reduced preview width. Avoid judging legibility while zoomed in.
Give each graphic one main reading task
Choose what someone should understand first. For a workshop announcement, that might be the topic, followed by the date and booking instruction.
If your graphic includes an introduction, five benefits, a speaker biography, and full terms, the problem is information density. Move supporting detail into the post text or split the content into a carousel.
Try this edit:
- Before: “Join our comprehensive introduction to making better product photographs with everyday equipment.”
- After: “Better product photos with your phone.”
The shorter version leaves space for useful details without shrinking every line.
Use contrast as a measurable check
The WCAG contrast guidance sets a 4.5:1 minimum for normal text and 3:1 for qualifying large text at Level AA, with defined exceptions. These are useful reference points for text and images of text.
Do not assume text qualifies as “large” just because it is large in your design file. The size at which people see it matters.
For text over photography, check the brightest and darkest areas behind the words. Add a solid panel, adjust the crop, or move the text when the background makes contrast unpredictable.
Choose sturdy letters and comfortable spacing
A very thin font may lose definition after resizing and compression. A heavy condensed font may fit more words while making them harder to distinguish.
Use a familiar, clear typeface for body text. Leave enough space between lines, and avoid long passages in all capitals. Keep decorative lettering for short phrases when it suits the design.
Do not communicate a distinction only through color. Label “approved” and “needs changes” rather than relying entirely on green and red.
Run a two-minute phone test
- Export one finished example.
- View it on a phone at normal size without zooming.
- Read the smallest essential text.
- Check the graphic against both light and dark surrounding interfaces.
- Ask someone unfamiliar with it to explain the main message.
If they struggle, shorten the copy or adjust hierarchy before adding decoration.
Finally, include essential information in the post text and add alt text. A readable image still needs an accessible text alternative.