Documents
What is a DjVu file?
DjVu is a format for scanned documents, most often books, journals, and archives. It compresses scanned pages far smaller than a typical PDF by separating text, background, and images into layers. The catch is that almost nothing outside specialized library and archive tools opens it natively.
- Extension
- .djvu
- Type
- Documents
- Typically
- Scanned books, archives
Why DjVu exists
DjVu was built in the 1990s specifically for putting scanned paper documents online, back when file size and bandwidth were tight constraints. Libraries, universities, and digital archives adopted it because a scanned book in DjVu could be a fraction the size of the same pages saved as a PDF.
The trick behind that size is layering. A DjVu page separates the sharp black text from the paper background and any photos or illustrations, then compresses each layer with a method suited to it. Text stays crisp, backgrounds compress hard, and the result is a small file that still looks like a clean scan.
The problem is reach. Web browsers don't open DjVu on their own, most phones and tablets have never heard of it, and mainstream reading and editing software skips it entirely. People usually meet DjVu when they download a scanned book or archived document and find nothing on their device will open it, so they convert it to PDF instead.
The trade-offs
Strengths
- Much smaller files than PDF for the same scanned pages
- Keeps scanned text sharp while compressing backgrounds heavily
- Long-established format for archived books and journals
Watch-outs
- Not supported by web browsers or most reading apps by default
- Rarely opens on phones or tablets without a special app
- Usually needs converting to PDF before you can read or share it normally
A note on privacy
A DjVu file usually doesn't carry personal metadata like GPS location, but scanned documents can still contain sensitive text, from IDs to personal letters to archived records. Running that scan through an online converter means the content of every page passes through someone else's server. Converting on your own machine keeps the document, and everything written on it, off the internet entirely.
Convert a DjVu file
Questions
How do I open a DjVu file?
Most everyday software won't open it. You'll typically need a dedicated DjVu reader, a library or archive app that supports it, or you can convert it to PDF, which opens everywhere without extra software.
Is DjVu better than PDF?
For pure file size on scanned pages, DjVu usually wins by a wide margin. For everything else, PDF wins: it opens in every browser, on every device, and in nearly all reading software without extra setup.
Why do archived books come as DjVu?
Digital archives and libraries adopted DjVu years ago because it kept scanned collections small on limited storage and bandwidth. A lot of older archived material is still stored that way today.
Can I convert DjVu without uploading it?
Yes. A desktop app like Morphjet converts DjVu to PDF on your own computer, so the scanned pages never leave your machine.
Morphjet opens and converts DjVu, one of 2,748 conversions it runs on your own computer. Available now.
One-time purchase, no subscription. 14 days to change your mind.