FormatDrop
Document Format Comparison

DjVu vs PDF — Scanned Book Format vs Universal Document

DjVu (pronounced 'déjà vu') was developed by AT&T Labs specifically for high-resolution scanned documents — books, magazines, academic papers. It achieves dramatically smaller file sizes than PDF for scanned content using a foreground/background separation technique. PDF is the universal standard but less efficient for scanned content. Most readers have never heard of DjVu; every device reads PDF.

DjVuvsPDF

Quick Verdict

Use DjVu when…

Keep DjVu if you need the smallest possible file size for scanned documents and have software to read it. Academic repositories use DjVu precisely because a 500-page scanned book can be 2 MB in DjVu vs 50 MB in PDF.

Use PDF when…

Convert to PDF for universal access. DjVu readers are rare — many modern devices have no DjVu support. PDF's 10× larger file size is often worth the universal compatibility.

DjVu vs PDF: Feature Comparison

FeatureDjVuPDF
Scanned document sizeVery small (2–4 MB for 300-page book)Large (20–100 MB for same book)
Image qualityExcellent for scanned text/diagramsGood — quality depends on scan settings
Device compatibilityPoor — requires DjVu plugin or appUniversal
Text search (OCR layer)SupportedSupported
Native browser supportNoneChrome, Firefox, Safari
E-reader supportVery few devicesKindle, Kobo, iPad

When DjVu wins

  • Scanned document size: Very small (2–4 MB for 300-page book)
  • Image quality: Excellent for scanned text/diagrams
  • Device compatibility: Poor — requires DjVu plugin or app

When PDF wins

  • Scanned document size: Large (20–100 MB for same book)
  • Image quality: Good — quality depends on scan settings
  • Device compatibility: Universal

Frequently asked questions

How do I convert DjVu to PDF?
Using DjVuLibre: `ddjvu -format=pdf input.djvu output.pdf`. Using Python: install djvu2pdf or use Calibre's conversion. Note that the PDF will be significantly larger than the DjVu.
Can I read DjVu files on Windows 10/11?
Not natively. You need a plugin like WinDjView, DjView, or the Sumatra PDF reader (which also reads DjVu). Converting to PDF is often easier than installing a DjVu reader.

Ready to convert?

Free, browser-based converters — no upload, no signup required.