1.4.5: Images of Text
One of the Level AA Success Criteria of the Web Content Accessibility Guidelines (WCAG) states that where possible, text should be used to convey information instead of images of text. Well-presented, eye-catching images of text and infographics have been used for a long time to get information across to users. However, they can be a detriment to the accessibility of a website or a digital document.
Unlike regular text, images of text cannot be customised to suit a user’s needs. People with low vision or visual tracking issues are unable to change the font, colour, spacing, or alignment of the text in an image because it has been fixed by a graphic designer. They can’t resize an image of text because this can cause it to become lower in quality and less readable.
On a mobile device, users will run into similar problems, where images – which are fixed in size and position – don’t adapt to different displays or screen orientations and therefore are more difficult to read. Screen readers and other assistive technologies aren’t able to read the text in an image at all and will rely on accurate alternative text to receive information. Automated translators also cannot translate images.
Any readable text presented in an image format, whether it is an infographic or simple headings stylised using bitmap, is considered an image of text. Where possible, web developers should consider conveying information through actual text instead of resorting to an image, or providing a text alternative.
However, there is no need to completely avoid using images of text. Exceptions to the rule include:
Web developers and graphic designers should note that to meet the latest accessibility standards, images of text must comply with Level AA Success Criterion 1.4.3 Contrast (Minimum), which states that text should have a colour contrast ratio of at least 4.5:1 against their background.
As part of our consultations, accessibility audits, and training sessions, we can explain all of the contextual nuances that would apply to the WCAG 2.1 Success Criterion 1.4.5 Images of Text. If you have any questions or need help with any digital accessibility issue, please don’t hesitate to contact IA Labs.