How to Quickly Convert PDF to Kindle Format with K2PDFOpt

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If reading is your pleasure then you must be hankering for an eReader. They are all the rage these days with Amazon’s Kindle, Sony, Nook, even the iPad and smartphones to a certain extent. Kindle is of course, at top of the pile right now. With the proprietary Kindle format (AZW), both Kindle 3 and DX support PDF files.

amazon kindle device

The AZW (Amazon Whispernet) format is better optimized for reading and publishing on the device. PDF eBooks don’t always render that well on the smaller screens of the Kindle so you might like to convert your PDF eBooks or documents to a more Kindle friendly format. Even though PDF is readable by the Amazon Digital Text Platform, you can make it better by optimizing text size, and a larger readable layout. ( Image courtesy gillyberlin )

Of the many PDF or Kindle converters, Kindle/PDF (K2PdfOpt) is one. It stands out for intelligent cropping and its batch processing features.

K2PdfOpt just doesn’t do a simple conversion; it maximizes the reading area of a PDF file and makes readability better on the 6-inch Kindle screens. It converts the PDF file to a bitmap and then automatically maximizes the viewing area by cutting, cropping, and reassembling the viewable areas. It removes excess white space and intelligently repaginates the original file to improve flow. Note that it does not make the pages flow seamlessly or remove footers as in Kindle’s default AZW format.

K2PdfOpt handles PDF files with two-column layouts particularly well. It auto-detects two-column documents. The other notable feature is that it also preserves the original fonts and graphics without dithering them unlike many other converters.

PDF Conversion

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The conversion process is fast and fully automatic. You can take a folder full of PDF documents and convert them into the Kindle friendly PDF format by the simple drag-drop process.

The PDF Conversion – Just Drag ‘N Drop

Drag and drop a single PDF document or a folder to the K2PdfOpt icon.

PDF Conversion

The conversion process is fast and the new PDF files are saved same place as the originals with “_k2opt” at the end of the name of each.

Retaining the original feel of the graphics and fonts comes at a price because the bitmap method increases the final file size. But that’s a small price to pay for a better reading experience. The bitmap conversion also handicaps searching within the document.

These few cons aside, K2PdfOpt is one of the best tools available for making your PDF files more Kindle friendly.

Saikat Basu
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Archived Comments

  1. willus says:

    Saikat–Your example is not very compelling because the border around the text is preventing k2pdfopt from separating the columns. Try running with a larger -m value, e.g. -m 1.0 (see the k2pdfopt help page). This will cause it to ignore anything within 1 inch of the edge of the page (i.e. the bounding box around the text). You’ll get a much better result.

  2. willus says:

    Actually, I just found your example and tried it out. -m 0.8 -odpi 220 gives a very nice result (you’ll need v1.14). I’ll probably update k2pdfopt so that for 2-column text it auto-fills the screen by default (so that you don’t have to select the right output dpi).

  3. James says:

    I’m getting my kindle for couple of days, and I’m looking for god way to convert some of my favorite books to kindle supporting file, from what I see there is no quality solution to do so. I’ll try of those program you suggest, hope it work for me.

  4. Aldrin Sy says:

    very informative article, will surely be helpful for kindle owners. Also to share my own tip, you can use free online tools like, to convert kindle clippings to pdf,word, or excel. you might also find this method useful. :)

  5. This might work OK for very occasional use, but I don’t see why PDF in any size is desirable to reading on screen.

    Calibre does a very good job of converting PDF text documents into suitable ebook formats. Includes tools for cleaning up headers, footers, page numbers etc – and also free.

  6. Nicole says:

    If i use your program to convert my pdf novels will it have the same issue i have with calibre. calibre is great for doing bulk conversions but i have repititive sentences. to many broken sentences with large spaces between text. does your program have the same issues?

    • willus says:

      Nicole–It’s hard to know without seeing your files. You have nothing to lose except a little time by trying it out. Note that k2pdfopt works differently from Calibre. It works at a graphical level rather than trying to OCR the document and render it as text. This has both advantages and drawbacks, and some files work well and some do not.

  7. the bugger says:

    where do you download the program? the article is ok, but the links send to discussions and more programs which does not help finally, becasue you open too many doors. I want to find an easy and straight forward program to convert PDF into kindle. Is it possible or do I have to struggle with one thousand different programs full of shit and advertisements? thanks.

  8. Swagato Barman Roy says:

    Why not use the software called ‘Calibre’? Deals with all possible book formats, recognizes all the readers available in market, knowing which of the formats suits best for your reader and takes care of conversion to device management.