"Pictures are for puppies, not for paragraphs"
- Mobile users struggle with images of text: the lines cannot reflow, so the browser just makes it smaller and smaller and smaller...
- Users with low vision struggle with images of text: JPG and PNG images of text cannot be scaled up by users with low vision without becoming blurry.
- Screen reader users struggle with images of text: all text in the image must be placed in the alternative text, in which all the text is read as a single run-on sentence: line breaks, headings, table structure and lists are lost, and if any words are missed the user cannot go back a line -- they have to start over at the beginning!
- Use "real" text as all page content you expect everybody to be able to read. Use CSS to visually style it to achieve dynamic visual designs.
- When images of text are absolutely necessary (e.g., logos):
- Always provide alternative text for words in a picture meant to be read.
- Upload vector images (SVG) or images with enough extra resolution to stay sharp when enlarged (e.g., a 1000px wide file for a 500px wide placement).
- If the text in the image is longer than a sentence, also reproduce its contents on the page as regular text: e.g., describe key points from a chart in its caption, or provide the event information from a poster designed for print next to the image of the poster.
Don't do This
Expect a User to Read a Picture of a Poster
Why Is This Wrong?
- This image cannot reflow for mobile.
- This image cannot be enlarged without becoming blurry.
- All formatting is lost for assistive devices; the alt text will be one run-on sentence.
Convert Poster to Text
Program of the Department Open House
All interested or curious sophomores are cordially invited.
12:30 p.m. to 1:30 p.m.
Tuesday, February 21st
209 Prospect House
Food will be served.
Download open House Flyer (.pdf)
Why Is This Better?
- The text can reflow for mobile.
- The text can be enlarged without becoming blurry.
- A screen reader user can jump between lines, skipping parts to skim or re-reading individual parts of interest. Even better, the header has been "pulled out" into the page structure to make it easier for them to find the event listing in the first place.
- Users who want to view the poster as a poster can click to enlarge it, and then view it full screen rather than crammed into a column.
Testing for Accessibility
Use this image bookmarklet or automated testing tool like WAVE to discover images on a page
- Are there images of text?
- If yes, can you set as live text or provide alternative format?
Things like logos, charts, and graphs can have text set as part of the image as long as alternative text is authored to provide equivalent access.