Checking contrast and text size in on-screen graphics

Check text in the exported video at the sizes viewers will see it. For text deliberately added to a graphic, assess contrast against its background, then size, display time and any covering element. A contrast ratio alone cannot show whether a small label stays readable when the graphic shrinks to a narrow player.

Identify text that carries the message

List titles, labels, numbers, callouts and instructions added to the video, especially chart labels, product conditions and interface results. If viewers cannot read them, the graphic may fail to explain the point even when the narration is clear.

Ask whether the audience needs each item’s exact wording. If so, enlarge it, simplify the graphic or show a closer view. Allow more time for long or unfamiliar terms.

Check whether captions or player controls cover important text. Move the graphic when needed rather than expecting viewers to hide captions.

Assess contrast on changing backgrounds

WCAG 2.2 Success Criterion 1.4.3 specifies at least 4.5:1 contrast for ordinary text and images of text, and 3:1 for large-scale text. It has exceptions, including incidental text and logotypes.

As a matter of good practice, consider font, size and contrast for overlay text. Use the ratios as design targets for deliberately added text, while assessing the applicable criterion and exceptions in context before making a conformance claim.

Check more than an easy frame. A white label over moving footage may read against a dark wall and disappear against a pale shirt. Inspect the least favourable backgrounds.

A solid panel or a different position can make the label more consistent. Measure using the intended foreground and background colours; a visual glance does not establish a ratio.

The WCAG “large text” category sets a contrast threshold, not a universal video font-size recommendation. A point size in an image editor may not match the text size after export and scaling. Record the contrast assessment separately from whether the delivered label is readable.

Contrast ratios for on-screen text in video graphics

Check the final viewing context

View a representative export in the intended page layout at narrow and larger widths. Read each label at normal playback speed. If a chart needs many tiny notes, show the conclusion in the video and make the fuller detail available in accompanying text. If a software control is too small, cut to a closer view for that step.

Check with captions enabled. Thin strokes, busy textures and compression can make lettering harder to distinguish even when the design colours seem sound. Increase the weight or simplify the background where needed. Essential on-screen information should also be available through audio or an appropriate description for viewers who cannot see it.

Key accessibility considerations for on-screen video text

Record a useful result

Note the time, text, background and requested change for each problem. Example: “At the result screen, enlarge the status label and put it on a solid dark panel.” Recheck the new export. A corrected design file does not establish what viewers receive; this review method is not evidence that an untested video meets WCAG.