Jack Tools

Contrast Checker

Check text and background colour contrast with a live preview, ratio result, and quick pass or fail guidance.

Choose your colours

Foreground colour

Background colour

Use this tool to compare foreground and background colours before using them in buttons, body text, banners, cards, and other interface elements.

Contrast ratio

—

Choose two colours to see the contrast result.

Preview heading

This is a sample paragraph so you can see how body text looks with your selected foreground and background colours.

Foreground HEX

#FFFFFF

Background HEX

#2563EB

Foreground RGB

255, 255, 255

Background RGB

37, 99, 235

Readability checks

Normal text —

Large text —

UI components —

How this contrast checker works

This contrast checker compares a text colour against a background colour and calculates how easy that combination is to read. It shows the contrast ratio and tells you whether the colour pair is likely to work for normal text, large text, and interface elements.

It is useful for websites, buttons, forms, apps, dashboards, banners, slides, and any design where text needs to stay readable against a coloured background.

The tool measures the brightness difference between your foreground and background colours. Stronger contrast usually makes text easier to read, while weak contrast can make body text hard to see, especially on smaller screens or in bright light.

Contrast ratio The ratio shows how different two colours are in brightness. Higher contrast usually improves readability.

Normal text Small body text usually needs stronger contrast than a heading or a large bold label.

Live preview The preview helps you check how the same colours look in real text and button-style examples.

Practical design use Use it to validate colour combinations for buttons, links, cards, banners, dashboards, and content blocks.

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Example contrast checker scenarios

White text on dark blue

Text colour#FFFFFF

Background#2563EB

Use caseCTA button or hero section

Typically strong readability

Light grey on white

Text colour#D1D5DB

Background#FFFFFF

Use caseMuted body text

Usually too weak for normal text

Black text on pale yellow

Text colour#111111

Background#FEF3C7

Use caseNotice box or info banner

Usually very readable

Dark text on bright green

Text colour#0F172A

Background#22C55E

Use caseStatus badge or button

Worth checking before small text use

Contrast Checker FAQs

It checks how readable a text colour is against a background colour by calculating the contrast ratio and showing whether that combination is likely to work for different text sizes and interface uses.

A contrast ratio measures the visual difference in brightness between two colours. Higher contrast usually makes text easier to read, especially for smaller body text.

Large text is easier to read than small body text, so it can still work with slightly lower contrast. Small text usually needs a stronger colour difference to stay readable.

Yes. This tool is useful for buttons, links, labels, icons, panels, cards, navigation, and any interface where text or graphics appear on top of a background colour.

Yes. Swapping colours is useful because a design may use one colour as text in one place and as a background in another. The tool helps you compare both directions quickly.

Good contrast helps more people read and use digital content comfortably, including users viewing screens in bright light and people who find faint colour combinations harder to distinguish.

No. Two colours can look attractive together and still be difficult to read when used for text and background. That is why contrast checking is important after palette selection.

It is accurate for normal colour contrast calculations and practical design checking. Final appearance can still vary slightly depending on screens, device settings, and the size or weight of the text in your design.