DjVu
Also known as: .djvu file, djvu format, scanned document format
DjVu is a file format built for storing scanned documents — books, manuscripts, and archives — at small sizes. It separates page text from background images so high-resolution scans compress far smaller than the equivalent PDF.
- Built for scanned documents and digitized books
- Often smaller than an equivalent scanned PDF
- Needs a dedicated viewer; convert to PDF to share
What DjVu is
DjVu (pronounced "déjà vu") was designed for digitizing print. It splits each scanned page into layers — sharp text and line art separate from the smoother background — and compresses each layer with the method that suits it, keeping files compact.
This makes it popular for scanned books and archives, where a long, image-heavy document in DjVu can be much smaller than the same scan saved as a PDF.
Opening and converting DjVu
DjVu is less universal than PDF. You typically need a dedicated viewer such as DjVuLibre, or a reader app that supports it, since most browsers and office apps do not open .djvu files by default.
To share a DjVu scan more broadly, convert it to PDF, which nearly every device can open. The PDF copy is usually larger but far more portable.