The short answer
- Open the fic in Ficshelf (any EPUB or HTML you downloaded) and press Save as clean EPUB.
- Send the EPUB to your Kindle library with Amazon's Send to Kindle: from the web, by email, or from the Kindle app.
- Open it in your Kindle library like any other document.
The file types Amazon accepts
Amazon's page on sending documents to your Kindle library lists these types for Send to Kindle: HTML (.html, .htm), RTF, Text (.txt), JPEG, GIF, PNG, BMP, PDF and EPUB. Its Send to Kindle by email page lists the same kinds of files plus DOC and DOCX.
| Format | On Amazon's list? |
|---|---|
| EPUB | Yes |
| HTML | Yes |
| Yes (a PDF stays a fixed page) | |
| MOBI | Not listed |
| AZW3 | Not listed |
Nothing here says Amazon removed anything. It says what Amazon's page lists today. If a MOBI or AZW3 file will not send, that is the first thing to check, and an EPUB is the type to try.
Three ways to send the EPUB
| Way | What Amazon says |
|---|---|
| Send to Kindle for Web | Upload documents of 200 MB or smaller directly from your device. Turn on Add to your library to download them on any device linked to your account. |
| Send the file as an attachment to your Send to Kindle email address, a unique address assigned to each compatible device and Kindle app on your account. Only approved addresses can send: the sender must be on your Approved Personal Document E-mail List. | |
| The Kindle app | Send documents to your library from the free Kindle app for iOS and Android. There are also Send to Kindle apps for Mac and Windows. |
What Ficshelf's EPUB contains
- A title page with the author, tags, summary and notes, then one file per chapter.
- A table of contents (an EPUB 3 navigation file plus a toc.ncx for older readers), the language of the fic and a modified time.
- Only plain formatting: paragraphs, emphasis, headings, lists, quotes, tables. Scripts and images loaded from the web are left out.
We checked the structure of the file: it unzips, the package lists every file, the contents point to every chapter, and a file written by Ficshelf reads back with the same title, author and tags. We did not have a Kindle at hand for this guide. If an EPUB from Ficshelf does not open on yours, write to info@peakappsstudio.com and say which Kindle it is.
Have the fic as an EPUB or HTML already? Open it, then press Save as clean EPUB. It happens in your browser.
Open your downloads in FicshelfFicshelf Pro, $8 paid once: search inside every fic, merge a series into one EPUB, a tidy ZIP of the whole library and a catalog as CSV. Get Pro on Gumroad or see what is free.
Questions
Why does AO3 to Kindle not work?
The first thing to check is the file type. Amazon's Send to Kindle page lists EPUB, PDF, HTML, TXT, RTF and some image types, and does not list MOBI or AZW3. Also check that the sender address is on your Approved Personal Document E-mail List, and that a web upload is 200 MB or smaller.
What format should I send from AO3 to Kindle?
EPUB is on Amazon's Send to Kindle list and keeps chapters and a table of contents, so it is the type to try first.
Does Send to Kindle accept MOBI or AZW3?
Amazon's page read on October 31, 2026 does not list them. It lists EPUB, PDF, HTML, TXT, RTF, JPEG, GIF, PNG and BMP.
How do I send an AO3 fic to my Kindle?
Save the fic as an EPUB, then upload it with Send to Kindle for Web, email it to your Send to Kindle address from an approved sender, or send it from the Kindle app.
Does Ficshelf send the file to my Kindle?
No. It makes the EPUB on your device; you send it with Amazon's own service.
Sources
- Amazon Customer Service: Learn About Sending Documents to Your Kindle Library. Read on October 31, 2026: the supported file types, the 200 MB limit of Send to Kindle for Web, and how the email address works
- Amazon: Send to Kindle by email. Read on October 31, 2026: the list of supported file types and the Approved Personal Document E-mail List
- AO3's download formats, from search listings (AO3's pages not opened). AO3 was offline on October 31, 2026, so its own help pages were not opened. Search listings describe the Download button on a work page as offering EPUB, HTML and PDF among its formats (some listings add AZW3 and MOBI)
Last checked: October 31, 2026. AO3 is not affiliated with Ficshelf, nor is the Organization for Transformative Works.