Color Contrast Checker
Sample text-run and background colors across a PDF and flag pairs that fall below WCAG-AA contrast ratios.
1. Upload your file
How does the Color Contrast Checker work?
Audit a PDF for low-contrast text. The tool rasterises up to 20 pages, samples a few text-bearing pixels per page, and computes the WCAG contrast ratio between the apparent foreground and background colours. Pairs below WCAG-AA (4.5:1 for normal text) are flagged with their hex colours and the actual ratio. This is a heuristic — it cannot perfectly identify which pixel is text versus background, and it samples only a few items per page — so confirm flagged pairs visually before fixing them in the source document.
🔒 Security & Privacy
All processing happens on your device. Your files never leave your browser, never touch our servers, and are not stored anywhere. Close the tab and the file is gone.
📱 Use it on any device
Works in any modern browser — Mac, Windows, Linux, iPhone, Android, and tablets. No installation, no app to download. Just open the page and start.
⚡ Quick & easy
Drag, drop, click. Most files process in seconds, not minutes. No watermarks added to your output, no per-day limits, and the tool always shows the result before asking you to download.
🎁 Always free, no signup
Free to use, every time. No account creation, no email required, no “trial” that converts to a paid plan. We make money from ads so you don’t have to pay.
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