Color Contrast Checker

PPI's contrast checker follows the WCAG 2.x targets: 4.5:1 for normal text and 3:1 for large text or icons meet the AA level most sites are built to, while 7:1 and 4.5:1 meet the stricter AAA level. Anything below 3:1 is unreadable for a meaningful share of viewers and should be changed before it goes to print or to a page.

PPI's contrast checker treats text as large once it reaches 18 point (24px) regular weight or 14 point (about 18.5px) bold. Large text gets a lower bar, 3:1 instead of 4.5:1, because bigger, bolder strokes stay legible at a weaker contrast than a small caption or body line does.

PPI's contrast checker converts each color to its relative luminance under the WCAG formula, then divides the lighter luminance by the darker one, each padded by 0.05. The result ranges from 1:1 (identical colors) to 21:1 (pure black on pure white), and it is the same formula every accessibility checker and browser dev tool uses.

PPI's contrast checker measures light, not familiarity. A color combination can look fine to someone who already knows what the logo says, while still falling below the ratio a low-vision viewer, a bright screen in daylight, or a printed sheet under office lighting needs to stay readable. The ratio is the objective floor; your eye is not a reliable substitute for it.

PPI's contrast checker measures light on a screen, not ink on a substrate, so a passing ratio is the starting point, not the finish. Fabric, ceramic and metal all absorb and reflect ink differently than a monitor renders it, which is why the tool lets you check your imprint color against the colors we actually stock and why a proof still matters before a full production run.

PPI's contrast checker computes the nearest passing shade of your text color by darkening or lightening it while keeping the same hue, so you get a real, working hex value instead of a vague suggestion to "pick something darker". Apply it with one click and the ratio recalculates instantly.

PPI's contrast checker matters for a product imprint just as much as a webpage, arguably more: a badge, banner or apparel logo has no zoom control and often gets read at a glance across a room. A one-color imprint that fails contrast against its garment reads as a smudge rather than a name or logo.

PPI's contrast checker includes a swatch strip of the colors we stock most, sorted by how many products carry each one, right below the tool. Pick one as your background to see whether your logo color will actually read on that tote, shirt or mug, then follow the link straight to the matching products.

Imprint size changes it a great deal. A large one-color logo survives a lower ratio because the shapes are big enough to read, while fine text and thin outlines need far more separation. When an imprint includes small lettering, treat the large-text threshold as a floor rather than a target.

PPI's contrast checker measures the ratio between two colors, which is one part of an accessibility review. It does not judge font size, spacing or screen reader behavior. Use it for the color decision and a full audit for a website or an app.

Material affects it noticeably. A matte tote scatters light and softens the difference between two colors, while a glossy tumbler reflects it and can create glare that washes an imprint out. The measured ratio is a reliable guide, but a shiny or textured surface deserves extra headroom.

Test against the product color, because that is the background your imprint will actually sit on. Testing against white flatters almost everything and tells you very little about how a logo will read on a navy tote or a black tumbler.

A white or reversed version of a logo is the standard answer for dark products, and most brand guidelines already include one. White on a dark background usually measures well above the threshold, which is why it is the safest single addition you can make to a brand kit for merchandise.