Guide

How do you convert MOBI to EPUB on a Mac?

The short answer is Calibre, and it takes about a minute. Here are the exact steps, what the conversion does to your formatting, why a DRM-protected Kindle book will refuse to convert, and when you do not need to convert the file at all.

Last updated 2026-09-14

The short answer: install Calibre, drag the .mobi file in, click Convert books, choose EPUB as the output format, and click OK. It is free, it runs entirely on your Mac, and a normal book takes a few seconds.

That is the whole procedure. The rest of this page is the part nobody tells you: what the conversion actually changes, the one case where it will refuse to work no matter what you try, and the case where converting is a step you can skip entirely.

The steps, in order

1. Install Calibre. Download it from calibre-ebook.com and drag it to Applications. It is open source and has been maintained since 2006.
2. Add the file. Open Calibre and drag your .mobi (or .azw3) file into the library window. It appears as a row with a cover.
3. Select it and click Convert books. The toolbar button is near the top. A dialog opens with the input format on the left and the output format on the right.
4. Set the output format to EPUB. It is the dropdown in the top-right corner of that dialog. Leave everything else alone the first time.
5. Click OK and wait. The job runs in the background; the progress indicator is in the bottom-right corner.
6. Get the file out of Calibre. Select the book, click Save to disk, and pick a folder. Calibre keeps its own library folder, so the EPUB will not appear next to your original file unless you export it.

If you convert a lot of books, select several rows before clicking Convert books — Calibre queues them and works through the list.

What the conversion does to the book

A format conversion is not a lossless copy. Expect these, in rough order of how often they bite:

• Page numbers change. EPUB is reflowable, so "page 214" from the MOBI does not survive. If you are citing a book, cite chapter and section, not page.
• Tables and complex layout degrade. Simple tables usually survive. Multi-column layouts, sidebars, and anything positioned with fixed coordinates usually do not.
• Footnote links usually survive; footnote placement may not. Notes can end up collected at the end of a chapter rather than where the original put them.
• Images survive, image quality is capped by the source. Converting does not add detail that was never in the MOBI.
• Text-to-speech markup, Kindle-specific popup footnotes, and X-Ray data are dropped. They are Kindle features, not book content.

For plain prose — which is most non-fiction and nearly all fiction — the result is clean and you will not notice a difference while reading.

The case where it will refuse: DRM

If Calibre reports that the file is not a valid MOBI, or the converted EPUB is a single page saying the book is protected, the file has DRM on it. Most books bought from the Kindle Store do.

This is not a bug and it is not something a setting fixes. DRM-protected files are encrypted for a specific account, and removing that encryption is illegal in many countries — including under the DMCA in the United States. We will not tell you how to do it, and you should not.

What you can do instead:

• Buy DRM-free. Standard Ebooks, Project Gutenberg, Verso, No Starch Press, Pragmatic Bookshelf, and many academic publishers sell or give away DRM-free EPUBs directly. Nothing to convert — you already have an EPUB.
• Check whether your book was ever DRM-free. Many Kindle titles from smaller publishers are. Calibre converting it without complaint is the test.
• Read it in the Kindle app. Amazon's own app on macOS opens your purchased library. It is the only legal way to read a DRM-protected Kindle purchase.

When you do not need to convert at all

Converting is a means, not an end. People usually convert MOBI to EPUB because they want to read the book in something other than the Kindle app. If that is your reason, a reader that opens MOBI and AZW3 directly skips the whole detour — no second copy of the file, no formatting loss, no Calibre library to maintain.

That is what Resage does on a Mac: it opens DRM-free MOBI, AZW3, EPUB, and PDF as they are, and you read the actual pages.

Convert when you genuinely need an EPUB — to send the book to a non-Kindle e-reader, to hand it to someone else, or to keep an archival copy in an open format. Skip it when all you wanted was to read the thing on your Mac.

Once the file is open, the harder problem starts

Format is the easy part. The part that actually stops people is the paragraph on page 90 of a dense book that will not resolve no matter how many times you read it.

Resage is built for that moment: the page stays in front of you, you ask about the sentence you are looking at, and the answer is drawn from that passage rather than from whatever a model half-remembers about the title. It also remembers what you have already worked through, so the second difficult chapter is explained in terms of the first.

FAQ

Is Calibre safe to use on a Mac?

Yes. Calibre is open-source software that has been actively maintained since 2006, and it runs entirely on your machine — conversions do not upload your books anywhere. Download it from the official site, calibre-ebook.com, rather than a mirror.

Can I convert MOBI to EPUB without installing anything?

Online converters exist, but you are uploading the full book to a stranger's server to get it back in another container. For a public-domain book that may be an acceptable trade; for anything you bought or wrote, it is not. Calibre does the same job locally.

Why is my converted EPUB missing the table of contents?

Calibre builds the EPUB table of contents from the structure it finds in the source file. If the MOBI had no proper navigation, use Convert books → Table of Contents and point Calibre at the heading level that marks chapters (usually h1 or h2), then convert again.

Should I convert AZW3 the same way?

Yes, the procedure is identical, and AZW3 usually converts better than older MOBI because it carries richer formatting. The same DRM restriction applies.

Does EPUB or MOBI look better on a Mac?

Neither format looks better on its own — the reader app decides. What differs is compatibility: EPUB opens in Apple Books, Calibre, and most third-party readers, while MOBI and AZW3 open in fewer of them. That compatibility, not visual quality, is the real reason to convert.