DjVu to PDF, ready to read

What a DjVu file is

DjVu is a file format made for scanned documents. It splits each page into layers, the sharp black text in one and the paper and pictures in another, and squeezes each one separately. That made it popular with digital libraries and with people sharing scanned books when downloads were slow, so a lot of old journals, reference works and out-of-print books online exist only as .djvu.

The catch is that few readers open it.

Which devices open DjVu

So you have two routes. Install a reader that understands DjVu, such as KOReader, which runs on some Kindle, Kobo, PocketBook and reMarkable devices and on Android. Or turn the book into a PDF, which every device on the list opens with its own software. Installing KOReader on each device is outside this page and we haven’t checked the steps.

Why a straight conversion disappoints

Free online converters will change .djvu to .pdf. What they don’t change is the page. You still get:

• the grey or yellowed background of the original scan
• wide margins and a dark scanner edge that shrink the text on a small screen
• pages that lean a degree or two
• no searchable text, or an old text layer from whatever OCR was used years ago

Those are the reasons the book was hard to read in the first place, and the format swap leaves every one of them.

How to turn a DjVu into a readable PDF

1. Upload the .djvu file. Up to 1,000 pages. It is turned into PDF pages as soon as it arrives, and your uploaded file is left as it was.
2. Set one crop. The pages are shown stacked, so a single box clears the margins across the book.
3. Let it clean and read. Each page is straightened, the paper turned white, the print black, and the text read and hidden under the page.
4. Look over flagged pages. Pages with pictures, odd crops or uncertain reading are marked. Keep the original of any page you prefer.
5. Download the PDF and send it to your e-reader.

Best suited for: old reference books, maths and physics texts, journal runs and dictionaries that circulate as DjVu.

Languages in older DjVu books

Many DjVu books are 19th and early 20th-century European texts. FixMyScan reads 19 languages, including English, German, French, Latin, Italian and Spanish, plus old German Fraktur type and Ancient Greek, and works out which ones a book uses from sample pages. A German book in blackletter with Latin footnotes needs no setting.

File size after converting

DjVu files are often small, so people worry the PDF will be huge. A grey scan saved straight into PDF can be. A cleaned one is different: text pages become black and white and are stored losslessly at one bit per pixel. Pages kept in greyscale for their pictures take more room.

If you plan to email the book to a Kindle, Amazon’s limit is 50 MB per email, or 200 MB through the Send to Kindle website. Our free will it fit check compares a file with each limit.

Keeping the original

Converting doesn’t touch your .djvu. Keep it if you use KOReader on one device and a stock reader on another. Uploads on our side are deleted 24 hours after the book is ready, or 24 hours after upload if you never convert it.

Questions