How to Convert DjVu Files to PDF — Rescuing Old Documents

What Is DjVu and Why Can't You Open It?

DjVu (pronounced "déjà vu") is a document format developed by AT&T Labs in the 1990s specifically for scanned documents. At the time, it was remarkable: a scanned 300-page book that would take 30–50 MB as a TIFF could be stored in 3–5 MB as a DjVu file without significant quality loss. The format used a layered compression scheme that separated foreground (text, line art) from background (paper texture, stains) and compressed each layer separately.

In the early 2000s, DjVu became the standard format for academic book digitization projects — Project Gutenberg, university library archives, Internet Archive, and Russian/Eastern European academic sites used it extensively. Tens of millions of scanned books exist in DjVu format.

The problem: DjVu never gained mainstream software support. Adobe Reader doesn't open it. Apple Books doesn't open it. No major e-reader supports it natively. You need a specialized plugin (DjVu Browser Plugin, which is deprecated) or a dedicated application like WinDjView or DjView — apps that aren't maintained and don't exist for mobile.

The practical solution is conversion to PDF, which opens on every modern device and platform without plugins.

What You Lose (and Don't Lose) When Converting

Before converting, it's worth understanding what DjVu → PDF conversion involves:

What you keep:

• All pages and their visual content
• Text searchability (if the source DjVu has OCR layer)
• Image quality (within the bounds of the source file)
• Bookmarks and table of contents (with some tools)

What you might lose:

• Some DjVu files have embedded OCR text layers that may or may not transfer cleanly to the PDF text layer, depending on the tool
• DjVu's background/foreground layer separation — PDFs render as flat images without this optimization
• The extreme compression — a DjVu file will typically become 2–4× larger when converted to PDF

The file size trade-off: DjVu's compression is genuinely superior to PDF for scanned documents. A 5 MB DjVu file might become 12–20 MB as a PDF. If storage is tight, the PDF compressor can bring the size back down after conversion, often achieving PDFs that are only 20–50% larger than the original DjVu.

Method 1: Converting DjVu to PDF Online

The easiest approach for occasional conversions is a document conversion tool. While DjVu isn't among the most common formats, the document converter handles document format conversions including DjVu → PDF workflows.

For multi-page DjVu books, online conversion tools process all pages and produce a single merged PDF — no manual page-by-page work required.

Method 2: DjVuLibre Command-Line Tools

DjVuLibre is the open-source DjVu library. On Linux/macOS, it includes command-line tools for conversion:

# Install DjVuLibre
# Ubuntu/Debian:
sudo apt-get install djvulibre-bin

# macOS (Homebrew):
brew install djvulibre

# Convert DjVu to PDF (all pages)
ddjvu -format=pdf -quality=85 input.djvu output.pdf

# Convert with higher quality (larger file)
ddjvu -format=pdf -quality=95 input.djvu output.pdf

# Convert specific page range (pages 1-50)
ddjvu -format=pdf -quality=85 -page=1-50 input.djvu output.pdf

# Convert single page
ddjvu -format=pdf -quality=85 -page=5 input.djvu page-5.pdf

The -quality parameter controls the JPEG compression applied to each page image in the output PDF. 85 is a good default — 70 for smaller files, 95 for maximum quality.

Method 3: Converting via ImageMagick

ImageMagick handles DjVu conversion using Ghostscript as a backend:

# Install ImageMagick with DjVu support
# Ubuntu: sudo apt-get install imagemagick djvulibre-bin ghostscript

# Convert DjVu to PDF
convert input.djvu output.pdf

# Convert with density setting (affects resolution)
convert -density 300 input.djvu output.pdf

# Convert multi-page DjVu (produces multi-page PDF)
convert input.djvu -compress jpeg -quality 85 output.pdf

Note: ImageMagick's DjVu support requires that DjVuLibre tools are installed on the system — ImageMagick calls ddjvu internally for DjVu files.

Method 4: Converting on Windows with WinDjView

WinDjView is the most capable free DjVu viewer on Windows and includes a print-to-PDF feature:

1. Download and install WinDjView
2. Open the .djvu file
3. Go to File → Print
4. Select "Microsoft Print to PDF" (Windows 10/11) or any PDF printer as the printer
5. Set page range and quality
6. Print to PDF

This works for any number of pages. The quality is controlled by the print driver's resolution settings — use 300 DPI for standard documents, 600 DPI for documents with fine detail.

Method 5: Converting on macOS with Preview

macOS Preview can open DjVu files if DjVu support is installed via a plugin. A simpler path:

1. Install DjVuLibre via Homebrew: brew install djvulibre
2. Use ddjvu from terminal (Method 2)

Or, use the free "DjVu To PDF" app from the Mac App Store — it uses DjVuLibre under the hood with a simple GUI.

Improving PDF Quality After Conversion

When a DjVu file contains low-resolution scans or poor quality source material, the converted PDF will reflect those limitations. If you need better-quality output:

Applying OCR to searchable text: If the DjVu file was scanned without OCR (text isn't selectable), use the PDF OCR tool on the converted PDF. This makes the text searchable and copyable, which is especially useful for academic documents.

Compressing oversized PDFs: If the converted PDF is too large, run it through the PDF compressor. For scanned documents, the "Image compression" setting typically reduces size by 40–60% with acceptable quality for reading.

Splitting large documents: If a converted DjVu book has hundreds of pages you want to separate into chapters, the PDF splitter handles that cleanly.

File Size Expectations

Here's what to expect when converting different types of DjVu files:

The ratio varies significantly by content type. Text-heavy academic documents with minimal illustrations convert at roughly 3–5× DjVu size. Illustrated content with color scans can be 4–8× larger.

Batch Converting Multiple DjVu Files

If you have a collection of DjVu files — from a digital library, archive download, or research collection — batch conversion avoids repeating the process manually:

# Batch convert all DjVu files in current directory to PDF
for file in *.djvu; do
  ddjvu -format=pdf -quality=85 "$file" "${file%.djvu}.pdf"
  echo "Converted: $file"
done

# Or using find for nested directories
find /path/to/djvu/collection -name "*.djvu" -exec sh -c \
  'ddjvu -format=pdf -quality=85 "$1" "${1%.djvu}.pdf"' _ {} \;

For batch conversion workflows and managing large file collections, see our batch processing guide for additional automation techniques.

Using Converted PDFs in Ebook Readers

Once you have a PDF, distribution to ebook readers is straightforward. For Kindle, Kobo, and similar devices that prefer EPUB over PDF, see our guide on EPUB vs PDF for ebooks — it covers when to use each format and how to convert between them.

For academic PDFs that need annotation, highlighting, or notes, a searchable PDF (with OCR text layer) works much better than an image-only PDF. Run your converted DjVu through the PDF OCR tool if the original didn't have searchable text.

Frequently Asked Questions

Why is my converted PDF so much larger than the DjVu file?

DjVu uses a specialized compression algorithm (IW44) that's specifically optimized for scanned document images. PDF doesn't support this algorithm — it stores page images as JPEG or PNG within the PDF container. The DjVu format also separates text foreground from background and compresses each independently, which PDF doesn't do natively. Expect 2–5× size increase; use the PDF compressor to bring it back down.

The text in my converted PDF isn't searchable. How do I fix it?

The original DjVu may not have had an OCR text layer (many scanned documents are image-only). After conversion, run the PDF through PDF OCR to add a searchable text layer via optical character recognition.

Can I convert DjVu to EPUB instead of PDF?

Not directly — there's no well-supported DjVu → EPUB path because EPUB requires reflow-capable text, not scanned images. Convert DjVu → PDF first, then run OCR to make the text selectable. Converting scanned-document PDF to EPUB with reliable text extraction is technically challenging and usually produces poor results unless the document is very clean.

My DjVu file has bookmarks/chapters. Will they transfer to PDF?

Some DjVu files embed a table of contents. The ddjvu tool from DjVuLibre preserves bookmarks in the output PDF. Third-party converters may not. Check the output PDF's bookmarks panel after conversion — if they're missing and you need them, DjVuLibre's command-line tools are more reliable.

DjVu pages look blurry after conversion. How do I improve quality?

Blurriness usually means low-quality source scans (the DjVu file itself has low resolution). Check the DjVu file's page resolution with djvudump input.djvu. If pages are below 150 DPI, the source is low-quality and conversion can't recover detail that wasn't captured. If they're 300+ DPI and still blurry after conversion, increase quality: ddjvu -format=pdf -quality=95.

Conclusion

DjVu is an excellent archive format stuck in a compatibility dead-end. Converting DjVu files to PDF gives you universal access across every device and platform — phones, tablets, desktop apps, web browsers — without installing deprecated plugins.

The ddjvu command from DjVuLibre is the most reliable conversion tool, available on Linux and macOS. Windows users can use WinDjView's print-to-PDF feature. For occasional conversions, the document converter handles the process online without any software installation.

After conversion, optimize your PDF's size with the compressor and add searchable text with OCR for a fully usable modern document from what was previously an inaccessible archive file.