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Presentation Contrast Checker
What contrast ratio do presentation slides need?
Presentation body text needs a contrast ratio of at least 4.5:1 against its background, and large headings and non-text marks such as icons, rules and chart bars need at least 3:1. These are the WCAG 2.2 AA thresholds. Palettes most often fail on tinted surfaces rather than on the slide itself.
Key takeaways
- WCAG 2.2 AA requires 4.5:1 for body text and 3:1 for large text and non-text graphics.
- Large text is defined as 18pt, or 14pt bold — most slide headings qualify, most slide body copy does not.
- A card or panel is usually the background tinted toward the accent, which moves the surface and can push a passing pairing below the threshold.
- Darkening or lightening a hue by a few percent is usually enough to clear a failing ratio while keeping the colour recognisable.
Check your palette
4 of 7 pairings fail — the fixes below keep your hue and move only as far as they must.
- Heading on slideYour titles17.85:1AAA
- Body on slideParagraphs and bullets4.76:1AA
- Accent as textEyebrows and highlighted words2.80:1needs 3:1try
#ED6D15(3.09:1) - Accent as a markIcons, rules, chart bars2.80:1needs 3:1try
#ED6D15(3.09:1) - Heading on a cardCard titles16.63:1AAA
- Body on a cardCard descriptions4.43:1needs 4.5:1try
#5F6E84(4.83:1) - Accent on a cardCard icons2.61:1needs 3:1try
#E06814(3.18:1)
Most contrast tools compare two colours. A deck has more than two, and the pairing that fails is rarely the one anybody checks — it is the muted body copy on a tinted card, or the accent icon on the panel behind it. This checks all seven pairings a slide derives from a four-colour palette, using the same logic Slideso's layout engine applies when it decides whether a generated deck is readable.
How to use the Presentation Contrast Checker
- Enter your four palette coloursSet the slide background, heading colour, body colour and accent. These four are what a deck's palette is normally defined by, and every other surface is derived from them.
- Read the seven pairingsEach row is a combination a slide actually renders: text on the slide, text on a card, and the accent used both as type and as a mark. The ratio and its WCAG grade are shown for each.
- Look at the card rows firstPairings on a card are where palettes usually fail, because the panel shifts the background away from the slide colour. A palette that passes on the slide can still fail inside a card built from it.
- Apply the suggested colourWhere a pairing fails, the nearest passing colour is shown alongside its new ratio. It moves as little as possible, so the result stays recognisably your brand hue.
Reference figures
| Measure | Value | Notes |
|---|---|---|
| Body text | 4.5:1 | WCAG 2.2 AA minimum |
| Large text | 3:1 | 18pt, or 14pt bold and above |
| Icons and rules | 3:1 | WCAG 2.2 non-text contrast |
| Enhanced (AAA) | 7:1 | Body text, stricter conformance |
| Pairings checked | 7 | Slide and card surfaces combined |
Frequently asked questions
What contrast ratio works on a projector?
Aim above the minimum rather than at it. Projectors lose contrast to ambient light, so a pairing that reads comfortably at 4.5:1 on a laptop can be unreadable from the back of a lit room. Treating 7:1 as the target for body text leaves enough headroom.
Does WCAG apply to presentations?
WCAG is written for web content, but the thresholds are based on human vision rather than the medium. A slide read from the back of a room is a harder case than a screen at arm's length, so the same minimums are a sensible floor.
Why does my palette fail only on cards?
A card or panel is usually the slide background tinted toward the accent colour. That shifts the surface your text sits on, so a pairing that clears the threshold on the plain slide can fall below it inside the card.
Can I still use my brand colour if it fails?
Usually yes, with a small adjustment. Darkening or lightening the hue by a few percent is generally enough to clear the threshold while the colour stays recognisable — which is what the suggested value does.
What counts as large text?
18 point, or 14 point bold and above. Most slide headings qualify for the relaxed 3:1 threshold; body copy and captions do not and need 4.5:1.
Do icons and chart bars need to pass?
Yes. WCAG 2.2 sets a 3:1 minimum for non-text content that conveys meaning, which covers icons, rules, and the bars and lines in a chart.
Sources
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Or let Slideso handle it
Slideso’s layout engine sizes the canvas, computes every slide’s geometry from real font metrics, and enforces contrast before you see the deck — so these checks are already applied by the time it hands you the slides.
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