NightPass™ Color Contrast Checker

WCAG 2.1 AA color contrast

Find every spot in a PDF that misses 4.5:1.The way a complainant would.

Each page is measured character by character in three PDF engines, read with OCR for text hidden in images, and checked for form fields, comments, hidden layers and graphics. Every failure is boxed on the page with its colors and ratio.

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You can also drag PDFs onto this box or paste one with ⌘V. Files stay in this browser; nothing is uploaded anywhere. The first run loads about 30 MB of PDF engines.

Activity

Test settings

Cross-viewer checkMeasure in Firefox's engine (pdf.js) and Chrome's engine (PDFium) as well as MuPDF. Read text in images (OCR)Finds text inside pictures, scans, outlined lettering and comment boxes. Boost faint text for OCRA second OCR pass on a contrast-stretched copy, so washed-out text is not missed. Graphics and UI (1.4.11)Icons, chart parts, lines, form field borders, checkbox and hover states. Hidden layersTurns on every layer that starts hidden and measures what appears. 100% zoom eyedropperWarns when thin or tiny text reads lighter than its true color at normal zoom.

Borderline warning band

Pages to check

Color Contrast Checker

Find every spot in a PDF that misses 4.5:1.The way a complainant would.

Every way the checker tests contrast

Client report