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“Kindle ebook format” can mean a file you upload to Amazon Kindle Direct Publishing (KDP) to publish a book, or a personal document you send to a Kindle library. The accepted formats and best choices differ by workflow: KDP supports EPUB, DOCX and KPF for reflowable books, while personal Send to Kindle transfers can accept EPUB and several other document types.
Which Kindle formats work for each task?
Start by identifying your workflow. Uploading a manuscript to KDP makes it a candidate for publication; sending a file to your own Kindle library delivers a personal document. An EPUB may be used in either workflow, but that does not make the workflows interchangeable.
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| Format or workflow | Use | What to know |
|---|---|---|
| EPUB uploaded to KDP | Reflowable or fixed-layout publishing | KDP accepts EPUB 2.0 and 3.0 files that meet its specifications. Validate the result with Kindle Previewer before publication. KDP’s MOBI support FAQ and supported manuscript formats explain the rules. |
| DOCX uploaded to KDP | Reflowable publishing | A common manuscript source. Most DOC/DOCX files convert, but complex formatting can convert poorly, so inspect the preview. KDP format guidance. |
| KPF uploaded to KDP | Publishing a book prepared with Kindle Create | Kindle Create exports KPF, which Amazon describes as its preferred path for KDP. Getting started with Kindle Create. |
| EPUB through Send to Kindle | Personal document transfer | Amazon lists EPUB among supported personal-document formats. This is separate from KDP manuscript acceptance. Send to Kindle file guidance. |
| PDF, DOC/DOCX, TXT, RTF, HTML and image files through Send to Kindle | Personal document transfer | These are also listed in Amazon’s transfer guidance. A document’s acceptance for transfer does not mean it is an accepted KDP manuscript format. Send to Kindle file guidance. |
| MOBI uploaded to KDP | Legacy publishing workflow | KDP no longer accepts MOBI for reflowable uploads from August 1, 2021, or fixed-layout uploads effective March 18, 2025. Previously published titles need no action unless updated. KDP’s MOBI support FAQ. |
Amazon’s cited KDP guidance is primarily US English-language guidance; it does not establish a complete country-by-country or device-by-device compatibility matrix. Support pages can change, so check the linked rules for your account and publication workflow.
Should the book be reflowable or fixed layout?
Layout is a publishing decision, not simply a file-extension choice. KDP converts an ebook to a Kindle format; choose the layout that preserves the book’s intended reading experience and features.
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Reflowable layout for text-led books
Reflowable books adapt to screen size and allow readers to resize text. They are generally the better fit for novels and other text-heavy books where reading comfort and adjustable settings matter. KDP’s comparison also identifies adjustable text settings and accessibility features as advantages. Amazon’s format comparison.
Fixed layout for designed pages
Fixed layout retains a set page design, making it useful for image-heavy children’s books or coffee-table books where placement and composition matter. The trade-off is that some fixed-layout formats can limit text selection, font controls or screen-reader support. Print Replica is not compatible with Kindle E Ink readers and lacks key accessibility features, including text resizing and screen-reader compatibility. Check the specific format’s restrictions before choosing it. Amazon’s format comparison.
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- Our fastest Kindle Paperwhite ever – The next-generation 7“ Paperwhite display has a higher contrast ratio and 25% faster page turns.
- Ready for travel – The ultra-thin design has a larger glare-free screen so pages stay sharp no matter where you are.
- Escape into your books – Your Kindle doesn’t have social media, notifications, or other distracting apps.
- Battery life for your longest novel – A single charge via USB-C lasts up to 12 weeks.
- Read in any light – Adjust the display from white to amber to read in bright sunlight or in the dark.
How should an author prepare and check a KDP file?
- Choose the layout. Decide whether readers need adjustable text (reflowable) or the designed page must remain fixed.
- Use a supported source. For a reflowable book, KDP lists EPUB, DOCX and KPF. For fixed layout, it lists EPUB and KPF; DOCX is not listed as a fixed-layout option. Consult KDP’s format FAQ.
- Prepare in Kindle Create if appropriate. Kindle Create exports KPF and EPUB. Its EPUB export is limited to reflowable books and does not support every Kindle feature, including image bleeds, drop caps and chapter-start imagery. KPF is the more complete Kindle Create export for KDP. Kindle Create guidance.
- Preview the converted book. Kindle Previewer can open EPUB, HTM/HTML, XHTML, OPF, KPF, DOC and DOCX files and preview appearance on Fire tablets, Kindle apps and Kindle E-readers. Its DOC/DOCX opening support is limited to English-language content. Kindle Previewer guidance.
- Fix conversion problems before publishing. Pay particular attention to complex formatting, image placement, page appearance and any interactive features the source format may not preserve.
If you cannot prepare a file yourself, Amazon identifies third-party conversion houses as an option and notes EPUB as a preferred output for KDP processing. Amazon’s paths to getting content on Kindle.
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No. The cited KDP guidance lists its supported manuscript formats as compatible with Kindle E Ink readers, Fire tablets and Kindle apps. A compatible book can therefore be read in an app; buying an e-reader is not a format requirement. Personal-document support is described separately in Amazon’s Send to Kindle guidance.
Rank #3
- Light and compact - With adjustable brightness, high contrast ratio, and fast page turns.
- Effortless reading in any light - Read comfortably with a 6“ glare-free display, adjustable front light—now 25% brighter at max setting—and dark mode.
- Escape into your books - Tune out messages, emails, and social media with a distraction-free reading experience.
- Read for a while - Get up to 6 weeks of battery life on a single charge.
- Take your library with you - 16 GB storage holds thousands of books.
What is the Send to Kindle file-size limit?
Amazon’s transfer help page states a 200 MB limit per file in its Mac transfer instructions. That is a Send to Kindle transfer limit, not a general ebook-format limit or a KDP manuscript rule. Check the current transfer instructions for the route you use. Amazon Kindle Support.
Quick Recap
Best Value
- Our fastest Kindle Paperwhite ever – The next-generation 7“ Paperwhite display has a higher contrast ratio and 25% faster page turns.
- Ready for travel – The ultra-thin design has a larger glare-free screen so pages stay sharp no matter where you are.
- Escape into your books – Your Kindle doesn’t have social media, notifications, or other distracting apps.
- Battery life for your longest novel – A single charge via USB-C lasts up to 12 weeks.
- Read in any light – Adjust the display from white to amber to read in bright sunlight or in the dark.
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- Our fastest Kindle Paperwhite ever – The next-generation 7“ Paperwhite display has a higher contrast ratio and 25% faster page turns.
- Upgrade your reading experience – The Signature Edition features an auto-adjusting front light, wireless charging, and 32 GB storage.
- Ready for travel – The ultra-thin design has a larger glare-free screen so pages stay sharp no matter where you are.
- Escape into your books – Your Kindle doesn’t have social media, notifications, or other distracting apps.
- Adapts to your surroundings – The auto-adjusting front light lets you read in the brightest sunlight or late into the night.
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