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Free AZW to MOBI converter. No sign-up — turn older Amazon AZW files into plain MOBI that opens on every Kindle.
To convert AZW to MOBI: upload your file using the form below, select MOBI as the output format, and click Convert. Our Calibre-powered engine processes the conversion in seconds with no registration required. The converter preserves text content, chapter structure, images, and metadata. For batch conversions of up to 50 files, upgrade to Pro.
Every AZW to MOBI conversion runs on the Calibre engine — the industry-standard open-source ebook library trusted by readers and tools worldwide. Calibre preserves fonts, chapter structure, and metadata far more faithfully than converters that rebuild files from scratch.
Drag & drop your file here
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AZW is Amazon's original Kindle format, introduced with the first Kindle in 2007. Under the surface it is a close cousin of MOBI: Amazon licensed the Mobipocket engine and wrapped it with its own DRM layer, producing the .azw files the earliest Kindle Store sold.
A few years later Amazon moved on to AZW3 (Kindle Format 8), a much richer format based on a modern HTML/CSS subset. AZW and AZW3 are not the same thing — AZW is the older, simpler one, closer to plain MOBI.
The practical upshot: if you have an old .azw that is DRM-free, converting it to MOBI is often close to a repackaging exercise, because the two formats share the same underlying structure.
MOBI is the foundational Kindle format. Every Kindle ever made reads it, from the 2007 original to the latest Paperwhite. It is simple, predictable, and maximally compatible.
That compatibility is exactly why you might want it. If a file needs to open on an unknown or older Kindle, MOBI is the format least likely to fail. The cost is presentation: MOBI drops embedded fonts and most CSS, keeping the text clean and readable rather than styled.
People often treat "AZW" and "AZW3" as the same label, but they are different enough to matter here.
AZW is the 2007-era format, essentially MOBI with Amazon's DRM. Converting DRM-free AZW to MOBI is straightforward.
AZW3 is the 2011-era format (KF8) with embedded fonts, real CSS, and fixed-layout support. It is a richer file and converts to MOBI by shedding those extras.
If your file is .azw3, use the AZW3 to MOBI converter instead — this page is specifically for the older .azw files. Mixing them up just sends you to the wrong tool.
1. Upload your AZW file. Drag it in or browse. Free accounts accept files up to 10MB, which covers virtually all AZW books.
2. Conversion runs. The AZW container is read, its content is simplified to MOBI-compatible HTML and CSS, and the chapter structure is rebuilt. Most files convert in well under a minute.
3. Download and sideload. Connect your Kindle by USB and copy the .mobi into the documents folder. It shows up on the home screen.
DRM blocks this entirely. Books downloaded from the Kindle Store carry Amazon's DRM and cannot be read by any converter. This works only on DRM-free AZW files you exported yourself, or titles from DRM-free sources.
You have an old DRM-free AZW. Maybe a personal export, a developer sample, or a book from a store that sold DRM-free AZW. Turning it into MOBI makes it open on any Kindle.
You want maximum compatibility. MOBI is the one format every Kindle reads. If you are handing a file to an older device or an unknown reader, MOBI removes the guesswork.
You are consolidating formats. Keeping one universal format for your personal library is easier to back up than a mix of legacy containers.
If your file came directly from the Kindle Store, it is DRM-protected and will not convert — no tool can decrypt it. In that case the only path is to download it through Amazon's own apps, which deliver a readable copy tied to your account.
Because AZW and MOBI share roots, the conversion is gentle.
Preserved:
No. AZW is Amazon’s 2007 format, essentially MOBI with DRM. AZW3 (KF8) is the 2011 format with embedded fonts and modern CSS. This page is for old .azw files; if you have a .azw3, use the AZW3 to MOBI converter instead.
No. Kindle Store books carry Amazon DRM and cannot be read by any converter. This works only on DRM-free AZW files such as your own exports or DRM-free purchases.
MOBI is the one format every Kindle reads, including the oldest models. If you want a file that opens on any Kindle without question, MOBI is the safest target.
Yes. AZW stores chapters as heading-based structure, and that maps directly to MOBI chapters, so reading order and breaks are preserved.
Amazon removed MOBI from Send to Kindle in 2022, so email delivery is rejected. Copy the file into the documents folder over USB instead.
Typical AZW books are 1-5MB, well within the 10MB free-account limit. Only image-heavy books risk hitting the cap.
Absolutely. All files are transferred over 256-bit TLS (SSL) encrypted connections. Your original file and converted file are automatically deleted from our servers within 1 hour. We never read, store, or share your content.
Deepen your understanding with expert conversion guides:
If you are an avid reader or self-published author, the biggest hurdle is often format compatibility. The short answer is: **Kindle users should use AZW3**, while **Kobo and other e-readers prefer EPUB**. MOBI is outdated for new devices. Use tools like [bookconv.com](/convert) or Calibre to convert your files instantly. For the head-to-head of the two formats themselves, see our [EPUB vs MOBI comparison](/blog/epub-vs-mobi).
Navigating the world of e-readers can be a maze of acronyms and incompatible formats. Whether you are a self-published author preparing a manuscript for launch or an avid reader trying to sideload your favorite library books, the question remains: which format actually works best for your device? This guide breaks down the compatibility of AZW3, EPUB, and MOBI for Kindle and Kobo devices, helping you choose the right format and convert your files effortlessly using free tools like BookConv.
Choosing the right eBook format is the single most critical step in self-publishing or digital distribution. If you are reading on a Kindle Paperwhite, you need AZW3 for the best experience; if you use a Kobo Clara or Nook, EPUB is the gold standard. Many authors and readers still struggle with the transition from the legacy MOBI format, which Amazon has largely deprecated in favor of more feature-rich containers. At BookConv, we see countless creators losing formatting fidelity by uploading uncompressed files to conversion tools. This guide explains exactly which formats your device supports, why AZW3 beats MOBI for Kindle users, and how to convert your manuscripts for free without ruining typography, footnotes, or metadata. For the direct EPUB vs MOBI decision, see our [full comparison guide](/blog/epub-vs-mobi).
Format explainers and in-depth comparisons:
You have an AZW3 book and an old Kindle that only reads MOBI. A direct AZW3 to MOBI conversion can strip advanced formatting, but a careful one keeps your book readable. Here is how to convert and what to expect.
Kindle won't open EPUB natively, and a careless EPUB to MOBI conversion scrambles your chapter breaks and drops your images. Here's how to convert cleanly with BookConv — free, in your browser, no software to install — and keep your layout.
AZW3, KFX, MOBI, EPUB — Kindle’s format soup confuses everyone. Here’s what each means, the safest format to convert to today, and how BookConv converts free in your browser with no software to install.
“BookConv saved me hours of manual work. I convert all my manuscript drafts to EPUB and MOBI in seconds. The quality is perfect — no formatting loss at all.”
Sarah Mitchell
Self-published author
“We use BookConv daily to help our patrons convert old LIT files to modern formats. It's fast, free, and requires no software installation. A must-have tool.”
James Rodriguez
Librarian
“I've tried many converters, but BookConv is the only one that handles FB2 and AZW3 without issues. The batch conversion feature is a game-changer for my workflow.”
Yuki Tanaka
Digital content creator