Convert AZW3 to EPUB Online — Read Kindle Books Anywhere

Break free from Amazon and read on any device or app you choose.

Drop up to 50 AZW3 files at once — no install, no sign-up required.

Drop AZW3 Files Here

50 MB per file Up to 50 files 3 parallel conversions 1 credit per 10 MB

Encrypted EU Servers Auto-delete 1h

Median AZW3 to EPUB time (last 10k jobs): 454ms

How it works

  1. 1 · Drop your files

    Drag & drop or choose AZW3 files. No account required—paid plans unlock bigger batches, higher limits, and priority queues.

  2. 2 · We convert securely

    Processed on our dedicated servers using Calibre. Encrypted in transit & at rest. We never store filenames—only file types & sizes for accounting.

  3. 3 · Download & auto-delete

    Grab your EPUB files in seconds. Files delete automatically after 1 hour. Delete anytime after downloading with one click.

AZW3, also known as KF8 (Kindle Format 8), is Amazon's modern ebook format introduced in 2011 with the Kindle Fire. AZW3 files use the .azw3 extension and support HTML5, CSS3, and advanced typography features not available in the older MOBI format.

Learn more: KF8/AZW3 on MobileRead Wiki

AZW3 offers superior formatting capabilities compared to MOBI, including custom fonts, embedded audio/video, SVG graphics, and complex layouts. It's the recommended format for modern Kindle devices (2012 and later), though older Kindles require the MOBI format.

EPUB (Electronic Publication) is an open ebook standard developed by the International Digital Publishing Forum (IDPF), now part of the W3C. First released in 2007 as a successor to Open eBook, EPUB has become the most widely supported ebook format. EPUB files are ZIP archives containing HTML/XHTML content, CSS styling, images, and metadata organized according to the EPUB specification.

Learn more: EPUB on Wikipedia

EPUB's key feature is reflowable content—text automatically adapts to different screen sizes, making it ideal for e-readers, tablets, and phones. The format supports embedded fonts, multimedia (in EPUB 3), and accessibility features. Most e-readers except Amazon Kindle natively support EPUB.

Frequently Asked Questions

What is AZW3 format?

AZW3 (also known as KF8 or Kindle Format 8) is Amazon's proprietary ebook format used on Kindle devices and apps. It supports advanced formatting features like HTML5 and CSS3, but is restricted to Amazon's ecosystem.

Why convert AZW3 to EPUB?

Universal Compatibility. EPUB is the most widely supported ebook format, readable on virtually all e-readers except Kindle (Kobo, Nook, Sony, etc.), tablets, phones, and computers. Converting to EPUB frees your ebooks from Amazon's ecosystem.

What devices support EPUB?

EPUB is supported by almost every e-reader including Kobo, Nook, Sony, PocketBook, and more. It also works on iOS (Apple Books), Android (Google Play Books, Moon+ Reader), and desktop apps like Calibre.

Can I convert DRM-protected AZW3 files?

No. DRM-protected AZW3 files (purchased from Amazon with copy protection) cannot be converted. You must remove DRM protection first using appropriate tools, or contact Amazon for a DRM-free version if available.

Will formatting be preserved?

Yes, Calibre preserves most formatting during conversion including chapters, images, fonts, and styling. AZW3's advanced KF8 features translate well to EPUB3's similar capabilities. Complex layouts may be slightly adjusted to ensure compatibility.

Is AZW3 the same as MOBI?

No. AZW3 (KF8) is Amazon's newer format with advanced formatting support, while MOBI is the older format. AZW3 files often contain both KF8 and MOBI content for backward compatibility. Our converter extracts the best available content for EPUB conversion.

Why leave Amazon's ecosystem? What are the benefits of EPUB?

Device freedom. EPUB is an open standard supported by virtually every e-reader except older Kindles: Kobo, Nook, Apple Books, Google Play Books, and dozens more. Converting to EPUB means you can read your books on any device, share with family members on different platforms, and aren't locked to Amazon's ecosystem.

How do I find my AZW3 files from Amazon purchases?

Connect your Kindle via USB and look in the documents folder. Amazon-purchased books are stored as .azw or .azw3 files. Important: Purchased books have DRM protection—you'll need to remove it before conversion using appropriate tools.

I have both MOBI and AZW3 versions—which should I convert?

Always prefer AZW3. AZW3 (KF8) contains higher-quality formatting, embedded fonts, and CSS styling that MOBI lacks. The EPUB output will be significantly better from an AZW3 source. Only use MOBI to EPUB if AZW3 isn't available.

What are the limits for this converter?

TierMax File SizeMax Files/BatchParallel Processing
Free50 MB50 files3 at once
Pro200 MB200 files6 at once
Business1024 MB1000 files10 at once

Note: File size limits are specific to this converter. Batch and parallel processing limits apply to all ebooks converters site-wide. See all converter limits →

How are credits calculated for this conversion?

Cost: 1 credit per 10 MB

How it works:

  • Files up to 10 MB: 1 credit (minimum)
  • 11-20 MB: 2 credits
  • 21-30 MB: 3 credits
  • 31-40 MB: 4 credits
  • Over 1024 MB: 103 credits (maximum cap)

Example: A 5 MB file = 1 credit. A 95 MB file = 10 credits.

Why per-megabyte? Larger files require more resources (processing, bandwidth, storage).

What are my daily and monthly credit limits?

Credit allocations vary by account tier:

TierDaily LimitMonthly Limit
Free50 credits/day
Pro10,000 credits/month
Business25,000 credits/month

Daily credits (Free tier, including guests) reset every day at midnight UTC. Monthly credits (Pro & Business) reset on your billing cycle date.

Note: With 1 credit per 10 MB, images under 10 MB cost 1 credit each. Pro users can convert 10,000 images per month.

Related Ebook Converters

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Limits shown for AZW3 to EPUB conversion. One subscription unlocks the entire Tools.FAST Network. Plans cover Convert.FAST, Compress.FAST, PDF.FAST (soon), and all future tools.

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  • 50 MB per file
  • 50 files per batch
  • 3 parallel standard conversions
  • 2 parallel AI conversions
  • 50 credits/day
  • Standard priority
  • Email support
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Pro

$9 /month

For independent work

  • 200 MB per file
  • 200 files per batch
  • 6 parallel standard conversions
  • 4 parallel AI conversions
  • 10,000 credits/month across Tools.FAST
  • High priority
  • Email & chat support
  • One subscription for the entire Tools.FAST network

Business

$19 /month

1 seat

For production scale

  • 1 GB per file
  • 1000 files per batch
  • 10 parallel standard conversions
  • 6 parallel AI conversions
  • 25,000 credits/month across Tools.FAST
  • Add seats to invite team members
  • Highest priority
  • Priority email & chat support
  • One subscription for the entire Tools.FAST network

How Credits Work

  • Usually 1 credit per conversion. Exact cost shown before you start.
  • Credits refresh monthly on your billing cycle.
  • Unused credits roll over, capped at your plan's monthly amount.
  • One subscription, all sites. Works across Convert.FAST, Compress.FAST, and future tools.

What's New in AZW3 to EPUB

Latest improvements to this converter

Last updated January 19, 2026
Jan 19, 2026

Initial release of AZW3 to EPUB converter for universal e-reader compatibility.