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Walter Bright

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Reading PDFs on the Kindle Fire

December 02, 2011

I've read a lot of reviews of the Kindle Fire, and they don't discuss something very important to me — reading PDF files on the Fire. I bought one anyway in the hopes that it would do a good job of it. Here's my review (additional aspects of the Fire are well covered by other reviews).

Why PDFs?

I'm a bibliophile. I have thousands of books (including great piles of obsolete programming and tech manuals). The problem is the sheer size and weight of them — I cower at the prospect of moving. I'm also a hoarder, and so am unable to throw them away. So I decided to scan them, which would enable me to throw the physical book away, and yet satisfy my hoarding compulsions. Plus, there are all the other benefits of a digital version, which you all know and I won't bore you with.

Scanning is straightforward and fairly quick. I slice off the spine with a stack slicer from ebay, and run the result through a hopper-fed scanner. It takes about 5 minutes for a regular paperback. It then takes an hour for the scanning software to do the OCR, but it does that unattended.

Unfortunately, the OCR makes enough mistakes that it becomes annoying to read the text. It isn't worth correcting the text, either, for a once-through read. OCR'ing also loses all the formatting. (But I OCR anyway just so I can grep for text.)

(My friend Brad gave me a great tip about proofreading OCR scans: Scan it and OCR it twice at two different resolutions, so each OCR will make different errors. Run the resulting two files through your favorite difference merger (I like meld), and you'll be able to quickly fix 90% of the errors.

I prefer the resulting PDF as a series of images of the book's pages; 300 dpi, black and white does the trick nicely.

On my older eink Kindle 3, though, reading the PDFs is a bit klunky. The screen is a tad too small, and the zoom was more or less unusable. Switching it to landscape mode did work tolerably well, but only with pocketbook-sized pages. Anything larger was hopeless. I was anxious to see how the Fire stacked up.

Getting the PDFs onto the Fire was easy. Just plug a USB cable into a Windows box and drag-and-drop. No iTunes or other special software is required. The PDFs go into the "Docs" section. Unfortunately, you'll have to supply the USB cable; the one from the Kindle 3 will work. There doesn't seem to be another way to get PDFs onto the Fire, as 30Mb files cannot be emailed to it, and the Fire cannot browse shared files on a LAN.

Opening the Docs section on the Fire shows them arranged on the shelves of a "bookshelf". They show up as white squares with the name of the PDF in black text on the white squares. Many PDF browsers will show the first page of the PDF as the icon for the file, but not the Fire. Just a white square.

Tapping on the square will open the PDF file. It fills the whole screen, with no borders or controls. Tapping on the left or the right edges will move backwards or forwards through the PDF. Finger swiping works, too, but it's slow. Back to the tap.

The great news is that extra inch of screen size over the Kindle 3 makes a huge difference. Pocketbook images are readable. Examining the rendered text under a magnifying glass shows that the renderer will smooth out the black and white jaggies by putting in a few grey pixels. The Kindle 3 does that, too, but does a slightly better job of it. Text at the same resolution looks marginally better on the Kindle 3.

Pinch to zoom works too (yay!), but it felt somehow wrong compared with pinch to zoom on an iPad. It took me a while to figure out why.

  1. The obvious difference is that zoom is smooth on the iPad, but a little jerky on the Fire.

  2. On the iPad, the zoom centers around the stationary finger and the moving finger enlarges it. On the Fire, the zoom centers around the center of the screen, always, no matter which finger moves.

  3. On the iPad, moving both fingers also moves the image. On the Fire, moving the image is done separately — take both fingers off, put one on, then push the image around.

2 and 3 show that on the iPad, zooming works just like putting two fingers on a stretchy piece of paper, and moving and resizing it. The Fire simply does not work like that — the paper does not "stick" under one's fingers. Zooming and recentering requires two separate operations.

On a positive note, it does work and it does get the job done.

I've been enjoying reading books on the Fire. I do get a little more eyestrain than using the e-ink Kindle, but I expected that. Reading on the Fire works best in low-light conditions, the e-ink is best in bright light.

While my review might seem a bit critical, on balance I am very pleased with the Fire and its PDF reading abilities. The few issues should be addressable with software fixes, and I hope Amazon will do so. Meanwhile, I'll be scanning-in the next box of books from the attic.

Thanks to Brad Roberts for helpful comments on this article.

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Actually this is the BEST article I've read on the subject. Documentation on this is rather slipshod. THANK YOU!


Hi Walter

I was reading your post on PDF documents on the Kindle and I was wondering if you tried our free PDF reader, qPDF Viewer ? The PDF format is a complicated format and maybe the default viewer that comes packaged with the Kindle is not yet fully features. I’d like to hear what you think about our app.

We also have a paid app called qPDF Notes which allows annotating, form filling and digitally signing PDF documents.
Both apps are available for download from the Amazon Android appstore.



Hi Walter,

Thanks for the article - never thought of scanning in all my old Zortech manuals... :-)

But I'm curious...

How is the Kindle at handling fillable PDF's inside the web browser?
Is there a reader, Adobe or otherwise, that launches PDF forms automatically from the pdf mime type, like Internet Explorer on the Kindle? (This is a big drawback to Apple's products.)



Kindle Fire has lightened up the mobile market for it has become the device with trust. It is that new entrant of the tablet series that focuses on e-reader capabilities. BYOD policy would be more secured if the users have Kindle devices as corporate data can be erased if the device is lost or if the user quits the firm.


Walter, thanks for the great articles. I have never been a fan of PDFs until I began using them on ebook readers, and found that properly formatted PDFs were quite readable even on low-end readers, i.e. Jetbook, et al. So a caution to those who also don't like PDFs, it may be the formatting that's the issue. There are screen settings such as reflow that really help, even two-column pages will show as a single continuous page.

The Kindle Fire is especially adept at PDF reading, though I highly recommend you visit the app store and get the Adobe reader. It's free, and has a few more useful options than the native Kindle viewer, though it took me a while to figure it out. Look to the top right of the screen for the page viewing options.

To select Adobe as the reader, you have to use a file manager to access the directory, else Kindle's default reader will boot. And speaking of file managers...

As to your comment about not being able to access LAN on the Kindle Fire, let me share this. Download the app ES File Manager, which is free. Once installed and running, look to the small word "LOCAL" in the upper left hand corner of the screen. A menu will pop up giving you the options Local, LAN, FTP and Bluetooth. Select LAN and then go to the menu (bottom) and select NEW then SCAN.

Your local LAN should show up, and any shared folders you have on your network's PC will allow you to COPY the file (hold your finger on the document until the OPERATIONS menu appears), then repeat the process from LAN to LOCAL, then navigate to your DOCUMENTS folder, and press anywhere in the window until the OPERATIONS menu appears again, and you can PASTE the document. There is also a slide-up clipboard that you can use, just depress the document located there and it will automatically PASTE the document.

It is a few steps to go through, but it's ideal in that you are no longer limited to the modest onboard memory of the Kindle.

You can also use WiFi File Explorer Pro, which assigns an IP address to your Kindle Fire, that you can access from your PC. Just type the IP address into your PC's browser, and you now have access to navigate your Kindle's file structure, including uploading files to it from your PC, no cable needed.

The WFFEP is a paid app, about $3, but it seems to do what is needed. There is a free version, but it doesn't allow uploading, just viewing and managing the Kindle's files.

My preference is still ES File Manager, as it's free, and you don't have to be physically at your computer to use it as long as you can access your LAN.

Sorry to be so wordy, hope this info is useful to someone.

- Dayne


Regarding the difference in the gestures, it's probably an effort to prevent being sued by Apple.



Appreciate your article on this topic - I have so many tech books (certainly not as many as you though!) & I've been considering a summer project of slicing / scanning / OCR'ing. Good to know that the Kindle Fire is a reasonable choice on the reader side. But what I'm really interested in is the equipment to convert the "dead trees" to PDFs.

I have to admit that I have been tempted to go out & find PDF versions of many of the books I've already bought, it's a bit of an ethical dilemma & I'm still not sure how I feel about it. At heart, I am still a paper guy - it's not uncommon for me to start my morning with an hour reading a couple chapters of a tech book before the kids are awake, highlighter in hand. But I travel a LOT (consultant), so there is something to be said for only carrying the bits around.

Anyway, just wanted to chime in & thank you for your post. I learned that there is a machine called a "stack slicer" (apparently also called a "stack cutter") - until now, I've used a Sawzall to cut off the binding & the results have been OK but I figure I might as well be using a chainsaw!