Is MOBI still supported on Kindle?

Amazon deprecated MOBI in August 2022. You can no longer send new MOBI files via Send to Kindle, and KDP no longer accepts MOBI for publishing. Existing MOBI files already on Kindle devices still work, but for anything new, use EPUB.

Can I still read my old MOBI files on Kindle?

Yes. MOBI files already in your Kindle library continue to work on your device. You just can't send new MOBI files to Kindle — use EPUB instead for any new content.

Should I use EPUB or MOBI for my ebook?

Use EPUB. It's the open standard accepted by Kindle, Apple Books, Kobo, Google Play Books, and every major reading app. MOBI is deprecated and not accepted by any major distributor for new titles as of 2022.

How do I convert a PDF to read on Kindle?

Convert the PDF to EPUB first using a tool like toolkit.bot, then send the EPUB to Kindle via the Send to Kindle website, app, or email. No MOBI conversion step is needed — Kindle accepts EPUB natively since September 2022.

EPUB vs MOBI: Which Format Should You Use? (MOBI Deprecated in 2022)

If you're wondering whether to use EPUB or MOBI for your ebook — use EPUB. Amazon deprecated MOBI in August 2022 and Kindle now accepts EPUB natively. Here's the full picture.

What happened to MOBI?

MOBI (and its successor AZW/AZW3) was Amazon's proprietary ebook format for Kindle devices. In August 2022, Amazon announced:

The Send to Kindle service stopped accepting MOBI files for new uploads
Kindle Publishing for KDP deprecated MOBI — publishers must now use EPUB
Kindle devices now accept EPUB directly — no conversion to MOBI needed

Existing MOBI files in your Kindle library still work. But for anything new, EPUB is the correct format.

EPUB vs MOBI: key differences

Feature	EPUB 3	MOBI/AZW3
Open standard	Yes (W3C/IDPF)	No (Amazon proprietary)
Kindle support	Yes (since Sept 2022)	Legacy only
Apple Books, Kobo, Nook	Yes	No
WCAG accessibility	Full EPUB Accessibility 1.1	Limited
MathML, SVG	Yes	No
KDP publishing	Preferred format	Deprecated
Send to Kindle	Accepted	No longer accepted

What to do with old MOBI files

If you have MOBI files in your library, you have two options:

Keep them on Kindle: MOBI files already on your Kindle device continue to work. You just can't send new ones.
Convert to EPUB: Use Calibre (free) to convert MOBI to EPUB — right-click any book → Convert books → Output format: EPUB.

What to do if you have a PDF and want it on Kindle

The workflow is now: PDF → EPUB → Kindle. No MOBI step needed.

Convert your PDF to EPUB at toolkit.bot/pdf2epub — free, handles academic layouts, scanned pages, and footnotes
Send the EPUB to Kindle via email, website, or app

The EPUB displays on Kindle exactly like a purchased book: Bookerly font, adjustable size, dark mode, Whispersync.

EPUB for publishing (KDP, IngramSpark, Apple Books)

If you're self-publishing:

KDP (Kindle Direct Publishing): upload EPUB 3 — Amazon converts internally for Kindle delivery
IngramSpark: requires EPUB 3 with EPUBCheck validation
Apple Books: requires EPUB 3
Kobo Writing Life: requires EPUB 3

MOBI is not accepted by any major distributor for new titles as of 2023. See the full publisher guide →

Convert your PDF to EPUB — send it to Kindle or publish on any platform.

Convert PDF to EPUB →