MOBI to PDF: Convert DRM-Free Kindle Books

There are two kinds of people searching for "MOBI to PDF." One has a folder of .mobi files from Project Gutenberg, an old Mobipocket library or a bundle they bought years ago, and wants them on something that isn't a Kindle. The other bought a book on Amazon and wants to print it.

The first person is about thirty seconds from a PDF. The second is going to be disappointed by every honest converter on the internet, including ours, and it's better to know that before you start.

Quick answer: To convert MOBI to PDF, open MOBI to PDF, drop in a DRM-free .mobi, .azw or .azw3 file, pick A4 or Letter, a font size and margins, and download a PDF with real, selectable text. It runs in your browser and uploads nothing. Kindle store purchases are encrypted with DRM and won't convert, and the newer .kfx format isn't supported.

MOBI, AZW, AZW3, KFX: Which Kindle File Do You Have?

The Kindle has used four file formats, and they're easy to mix up because Amazon reused the same structure for most of them.

MOBI

The original. It came from Mobipocket, a French e-reader company Amazon bought in 2005, two years before the first Kindle (Wikipedia). Inside is simple HTML in an old Palm database container. Free libraries and indie stores handed these out for a decade.

AZW

Essentially a MOBI file with Amazon's DRM and a different serial-number scheme. It's what the Kindle store delivered for years.

AZW3 (KF8)

Arrived with the Kindle Fire in late 2011. It added a subset of HTML5 and CSS3, so books could have better layout, and many AZW3 files still carry an old-style MOBI copy inside for older devices.

KFX

The newest, with Amazon's enhanced typesetting. Recent Kindles download store books in it, and it's a different container altogether.

The extension doesn't tell you about DRM. A .azw3 you downloaded from Project Gutenberg converts fine. A .azw from your Kindle's storage almost certainly doesn't. What matters is where the file came from.

Why Kindle Store Books Won't Convert

A Kindle store book is encrypted with a key tied to your Amazon account and devices. A converter that opens the file finds scrambled text records where the chapters should be. There's nothing to convert unless you break the encryption, and removing DRM is exactly the step US law (and the law in many other countries) prohibits, even for books you paid for. Our EPUB to PDF guide covers the legal side in more detail; it's the same for Kindle files.

Amazon has also closed the route people used to get the files at all. Since February 26, 2025, the Kindle website no longer offers "Download & Transfer via USB" for purchased books. And newer purchases arrive as KFX, which most converters can't read even when there's no DRM.

So MOBI to PDF checks every file before it converts it. It reads the encryption flag in the book's header, and if it's set, you get a clear message, "This Kindle book is protected by DRM and cannot be converted," instead of a PDF full of garbage. We won't point you to DRM-removal plugins, and you should be suspicious of any converter site that quietly accepts store books.

Where DRM-Free Kindle Files Come From

More places than people expect:

• Project Gutenberg offers almost every book in two Kindle versions: AZW3 for current Kindles and MOBI for older ones. We tested with both.
• Standard Ebooks publishes carefully proofread public-domain editions with an AZW3 download.
• Publishers and authors who sell DRM-free, and most ebook bundles, often include MOBI alongside EPUB and PDF.
• Your own files: a manuscript exported with Kindle Previewer or the discontinued KindleGen, or a book you converted with Calibre.

If you have the same book as an EPUB, use that instead, through EPUB to PDF. Publishers usually make the EPUB first, and the Kindle file is generated from it, so the EPUB is the better source.

What the PDF Looks Like

A Kindle book has no pages. Text reflows to whatever screen and font size you pick, so a converter has to typeset the book from scratch. Ours uses the same typesetting engine as EPUB to PDF: it flows the chapters onto A4 or US Letter pages in Noto Serif, starts each chapter on a new page, numbers the pages, and puts the cover, title and author on a title page.

We converted Project Gutenberg's Frankenstein to check what you get:

Both came out under 600 KB with every word selectable and searchable, because the text is drawn as text rather than as pictures of pages. The slightly different chapter counts come from the two files being built differently; the text is the same. Turn the font size up and the page count rises with it: the MOBI went to 231 pages at 14 pt.

Some things don't survive the trip, on purpose:

• Publisher styling: the book's own fonts and CSS are replaced by the tool's typography.
• Inline italics and bold inside a paragraph become regular text. That's the loss you'll notice most in fiction.
• Tables are flattened to text, one row per line.
• Navigation: the PDF has page numbers but no clickable table of contents or bookmarks.

AZW3 files usually convert a little better than old MOBI files because the tool reads their newer HTML layer, so if you have both, pick the AZW3.

How to Convert MOBI to PDF

1. Open MOBI to PDF and choose a .mobi, .azw or .azw3 file. It's parsed in your browser, and you'll see the title, author and the list of chapters it found, so you can spot a missing one before converting.
2. Pick a page size: A4 or Letter. Choose the paper you'll print on, or A4 for a tablet.
3. Set the font size, from 8 to 24 pt (11 by default). Larger type means more pages, so 12 to 14 pt is a good middle for reading on a tablet.
4. Set the margins, from 0.5 to 1.5 inches. Go wide if you plan to write notes in them.
5. Convert and download the PDF.

From there it's an ordinary PDF. Mark it up with Annotate PDF, pull out one chapter with Extract Pages, or print two pages per sheet with N-up to save paper. If the book uses a script our serif font doesn't cover, like Chinese or Arabic, the tool falls back to Noto fonts for those characters and warns you if any are still missing.

Your Library Stays on Your Machine

Your reading history says a lot about you. MOBI to PDF unpacks and typesets the book entirely in your browser tab, so the file is never uploaded, and there's no queue, account or size cap. The same goes for every tool here; why local-first PDF tools explains why.

Frequently Asked Questions

Can I convert Kindle books I bought on Amazon to PDF?

Not with this tool, and not legally with most others. Kindle store books are protected with DRM, and removing it is prohibited in the US and many other countries even for books you own. MOBI to PDF detects DRM and tells you instead of producing a broken file.

Is MOBI the same as AZW3?

Close relatives. Both are Amazon formats built on the same Mobipocket container. AZW3 (also called KF8) added HTML5 and CSS3 support in 2011 and often carries an older MOBI copy inside for compatibility. MOBI to PDF reads both.

Does MOBI to PDF support KFX files?

No. KFX is a different format from MOBI and AZW3, and Kindle store books in KFX are also DRM-protected. If you have a DRM-free version of the book in another format, convert that instead.

Will the PDF keep the book's formatting?

It keeps the structure: chapters, headings, paragraphs, block quotes, images and the cover. It re-sets the text in its own serif font, so publisher fonts, inline italics and complex layouts don't carry over, and the page count depends on the page size and font size you pick.

Is a MOBI or an EPUB better for converting to PDF?

The EPUB, if you have both. Kindle files are usually generated from an EPUB, so the EPUB is closer to the source. Use EPUB to PDF for it.

Have a DRM-free Kindle file you want to print or annotate? Convert your MOBI to PDF in your browser. Nothing is uploaded.