Make a PDF more readable — improve font, contrast and accessibility

2 min read·25 July 2026

A PDF that is hard to read wastes time and causes frustration. Whether it is a poorly scanned document, text that is too small or insufficient contrast — there are several ways to improve the readability of a PDF.

Improve scanned PDFs with OCR

A scanned PDF is often blurry or skewed. OCR (Optical Character Recognition) makes the text searchable and readable — use PDFrust OCR. For better scan quality: rescan the original at minimum 300 dpi. Some scanners have an "auto enhance" option that improves sharpness and contrast.

Adjust contrast and brightness

Scanned documents are sometimes too light (faded) or too dark (black blotches). Best approach: use the contrast/brightness setting in your scanning app. Afterwards in a PDF, you can visually increase contrast by converting to grayscale (PDFrust Grayscale). Full black-and-white rendering helps with light, faded originals.

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Embed fonts for consistency

If a PDF is opened on a device with a different font, the text can look different or compressed. When exporting from Word/InDesign, ensure fonts are embedded in the PDF. In PDFrust you can use Flatten to "freeze" the PDF so fonts always display correctly.

Night and dark mode for readers

Want a PDF that is also readable in dark mode? Use PDFrust Invert Colors to turn a white background black with white text. Ideal for e-readers and night readers. Note: images are also inverted — choose deliberately which pages to invert.

Accessibility: readable by screen readers

For blind or visually impaired users, a PDF must be searchable (OCR) and have a logical reading order. PDF/UA is the accessibility standard — it requires advanced software (Adobe Acrobat Pro) to implement fully. Basic step: always run OCR on scanned documents.