You have an .azw3 file and you want to read it on your iPhone or iPad. You tap the file, and iOS offers to open it with… nothing useful. That’s because AZW3 is Amazon’s Kindle format, and Apple doesn’t support it natively.
Here’s how to actually read AZW3 files on your iPhone or iPad.
What Is AZW3?
AZW3 — also called KF8 (Kindle Format 8) — is Amazon’s modern ebook format. Under the hood, it’s based on HTML5 and CSS3, similar to EPUB. But it’s wrapped in Amazon’s proprietary container, so only apps that explicitly support it can open it.
You’ll encounter AZW3 files from:
- DRM-free Kindle purchases that you’ve downloaded from Amazon
- Humble Bundle and other stores that offer Kindle-compatible formats
- Calibre conversions — it’s a common output format
- Online collections that distribute in multiple formats
Important: Most Kindle books purchased from Amazon are DRM-protected. DRM-protected AZW3 files can only be opened in the Kindle app. The methods below work for DRM-free files only.
Your Options
Option 1: Import into BookShelves (Easiest)
BookShelves reads AZW3 files directly on iPhone and iPad — no conversion needed. The app automatically converts AZW3 to EPUB during import, preserving formatting, fonts, images, and cover art.
How to do it:
- Download BookShelves from the App Store
- Find your
.azw3file — in Files, an email attachment, or a download - Tap the file and choose Open in BookShelves, or use the Share menu and select BookShelves
- The book appears in your library — start reading
That’s it. No computer needed. The conversion happens on your iPhone or iPad in the background.
From there you get adjustable fonts, themes, bookmarks, highlights, and full-text search. If you have BookShelves on your Mac too, your library syncs automatically via iCloud.
BookShelves also handles MOBI, PRC, and AZW files — the older Kindle formats. See How to Read MOBI and AZW Files on Mac for the Mac-specific guide.
Option 2: Use the Kindle App (Amazon Books Only)
Amazon’s free Kindle app for iOS can read AZW3 files, but only books tied to your Amazon account. You can’t import arbitrary AZW3 files into the Kindle app — it’s designed for books you’ve purchased or sent through Amazon’s “Send to Kindle” service.
If your AZW3 file came from Amazon with DRM, the Kindle app is likely your only option.
Option 3: Convert on Your Mac First
If you have a Mac, you can convert the AZW3 to EPUB before sending it to your iPhone:
- BookShelves on Mac — drag the AZW3 file into BookShelves. It converts automatically, and the EPUB syncs to your iPhone via iCloud.
- Calibre — convert AZW3 to EPUB using Calibre, then transfer the EPUB to your iPhone via AirDrop, iCloud Drive, or email.
This adds a step but gives you a standard EPUB file that works in any reader.
AZW3 vs. EPUB
AZW3 and EPUB are technically similar — both use HTML and CSS under the hood. The key differences:
| AZW3 | EPUB | |
|---|---|---|
| Creator | Amazon | Open standard (W3C/IDPF) |
| App support | Kindle apps, BookShelves, Calibre | Nearly every ebook reader |
| DRM | Amazon’s proprietary DRM | Adobe DRM or DRM-free |
| iOS native support | No | No (but far more apps support it) |
When BookShelves converts AZW3 to EPUB, the result is a standard, open format that works everywhere. The conversion preserves formatting, fonts, images, and metadata — you won’t notice a difference in reading quality.
For a broader format comparison, see EPUB vs PDF.
What About Other Kindle Formats?
| Format | Extension | BookShelves Support |
|---|---|---|
| AZW3 / KF8 | .azw3 | Yes — auto-converts to EPUB |
| MOBI | .mobi | Yes — auto-converts to EPUB |
| PRC | .prc | Yes — auto-converts to EPUB |
| AZW | .azw | Yes — auto-converts to EPUB |
| KFX | .kfx | No — Amazon’s latest DRM-only format |
All supported Kindle formats are automatically converted during import. The original file is preserved — BookShelves creates a clean EPUB for reading.
Tips
- Try BookShelves first. It handles AZW3 directly on iPhone — no Mac, no conversion tools, no extra steps.
- DRM is the main blocker. If a file won’t import, it’s almost certainly DRM-protected. DRM-free sources include Humble Bundle, Smashwords, StoryBundle, and authors who distribute directly. See our DRM-free ebook stores guide for more sources.
- AZW3 converts better than MOBI. If you have both versions of a book, use the AZW3 — it’s the newer format and produces a cleaner EPUB with better formatting.
- Check your library after import. BookShelves automatically looks up metadata and cover art, but occasionally a book needs a manual correction.
See the full feature list to explore everything BookShelves offers.
Related Guides
- Best eBook Reader Apps for Mac and iPhone — comparing reading apps beyond Apple Books
- 30 Best Free Classic Books — public domain EPUBs you can start reading right now
- How to Read EPUB Files on Mac — getting started with EPUBs on macOS
