Kindle transfer guide

How to Send PDFs (and EPUBs, Docs, MOBI) to Kindle: Every Method

To send a PDF to Kindle, you have four main options: Send-to-Kindle email, the Send-to-Kindle mobile app, USB cable transfer, or convert to KFX and sideload. All four work — but they differ on file size limits, format support, and how well they preserve multi-column layouts, footnotes, and heading structure in the converted result.

By Joe Fowler — Updated May 17, 2026

Which method should you use?

The right method depends on your file type and what you need the result to look like. Send-to-Kindle email and the app are the most convenient — no cable required — but Amazon converts your file during delivery, which breaks multi-column layouts and drops footnote links in academic PDFs. USB cable transfers the original file without conversion but requires a cable. KFX sideloading via leafbind gives the best result for complex PDFs at the cost of an extra conversion step.

Quick reference

For a simple PDF — one column, no footnotes — Send-to-Kindle email is the fastest option: email the file to your Kindle address, it arrives in minutes. For academic papers with two-column layouts or tappable footnote links, Send-to-Kindle's conversion strips that structure; use USB cable to transfer the original file, or convert to KFX with leafbind first. EPUB files work natively via Send-to-Kindle email and the app (DRM-free only). MOBI files are not accepted via email or app (Amazon removed MOBI support in 2022); use USB cable for MOBI. For files over 50 MB, only USB cable transfer works without size restrictions.

File type	Send-to-KindleEmail	Send-to-KindleApp	USBCable	leafbind→ KFX
PDF	✓50 MB max, converted	✓50 MB max, converted	✓original file, no limit	✓→ KFX, best quality
EPUB	✓DRM-free only	✓DRM-free only	✓DRM-free, native	—
DOC / DOCX	✓converted	✓converted	⚠limited support	—
MOBI	✗removed 2022	✗removed 2022	✓native	—
AZW3	—	—	✓native	—
TXT / RTF	✓converted	✓converted	✓basic reading	—

✓ supported · ⚠ limited support · — not applicable. Amazon's Send-to-Kindle help page lists the current supported personal document types.

Method 1 — Send-to-Kindle Email

Every Amazon account includes a Send-to-Kindle email address — a personal @kindle.com address that accepts personal documents. Email a file to that address, and it appears in your Kindle library within minutes. No software to install, no cable required.

Before the first use, you must add your sending email address to Amazon's Approved Personal Document E-mail List. Amazon silently drops documents from unapproved addresses — no bounce email, no notification. To add an address: go to amazon.com/mycd → Preferences → Personal Document Settings → Approved Personal Document E-mail List.

For PDFs

Attach the PDF to an email and send it to your Kindle address. Leave the subject blank — Amazon converts PDFs to Kindle format automatically during delivery. The 50 MB size limit applies.

Important: Amazon's conversion strips PDF layout. Multi-column text gets interleaved — both columns read line by line as they appeared on the printed page, not column by column. Footnotes are detached from their in-text citations. Section headings often lose their hierarchy, removing the navigable chapter list. For simple single-column PDFs (books, reports, prose), the result is usable. For academic papers with two-column layouts and footnotes, the conversion degrades readability significantly.

If you need the PDF to read correctly on Kindle — particularly a research paper, journal article, or technical document — the Send-to-Kindle email method is not the right choice. See Method 4 (KFX conversion) for the alternative.

For EPUBs

Amazon added native EPUB support in 2022. Attach a DRM-free EPUB to an email and send it to your Kindle address — it delivers as an EPUB, not converted to AZW. EPUB files with DRM (copy protection from commercial ebook stores) are not accepted; only DRM-free files work.

The 50 MB limit applies to EPUB files. Most EPUB files are well under this limit — typical ebooks are 1-5 MB.

For documents (DOC / DOCX / TXT / RTF)

Microsoft Word files (DOC, DOCX), plain text (TXT), and RTF are all accepted. Amazon converts them to Kindle format for delivery. For Word documents, formatting is preserved reasonably well — paragraph styles, bold, italic, and lists carry over. Complex tables and precise layout do not.

For MOBI files

Amazon deprecated MOBI from Send-to-Kindle email and the app in 2022. Attaching a MOBI file to a Send-to-Kindle email will not deliver — the file is rejected at Amazon's server. MOBI still works via USB cable: copy the file into the Kindle's Documents folder and it opens normally on supported devices. If you have MOBI files from older Calibre conversions, USB sideload (or converting them to EPUB or AZW3 first) is the path forward.

Method 2 — Send-to-Kindle App

Amazon's Send-to-Kindle app is available for iOS and Android and works as a share sheet extension. On iOS: open a PDF in any app, tap Share, then choose Send to Kindle. On Android: open a file in Files or another app, tap Share, then Send to Kindle.

The app delivers the same formats as the email method (PDF, EPUB, DOC/DOCX, RTF, TXT, HTML, and common image formats) with the same 50 MB limit and the same conversion behavior for PDFs. MOBI is not accepted via the app — Amazon deprecated MOBI from Send-to-Kindle email and app in 2022; USB sideload is the path for MOBI files. The main advantage over email is convenience — no email client required, and the share sheet integration works from any app that can share files.

The app requires your sending device's Amazon account email address to be on your Approved Personal Document E-mail List, the same as the email method. If the app is sending but files are not appearing, this is the first thing to check.

The desktop Send-to-Kindle extension for Chrome and Edge works by right-clicking a PDF link in the browser and choosing “Send to Kindle” — it opens a dialog to select your device. This is useful for papers found through Google Scholar or publisher sites.

Method 3 — USB cable transfer

Connecting your Kindle via USB and copying files directly is the simplest method for files that don't need conversion — and the only method without a file size limit.

On Windows

Connect your Kindle with its USB cable (USB-C for Scribe, Paperwhite 5+; micro-USB for older models)
Open File Explorer — the Kindle appears as a removable drive under This PC
Open the Documents folder on the Kindle drive
Copy your PDF, EPUB, MOBI, or KFX file into the Documents folder
Safely eject the Kindle using the Safely Remove Hardware option in the taskbar
The file appears in your Kindle library immediately after ejection

On Mac

Connect via USB — the Kindle appears on the Desktop or in Finder under Locations
Open the Documents folder on the Kindle volume
Drag your file into the Documents folder
Eject using the eject button in Finder before disconnecting

USB cable transfers the original file without any conversion — the PDF arrives as a PDF, not reprocessed. For PDFs, this means the same layout limitations apply when Kindle renders it: multi-column text and footnotes will have the same problems as the email method. The difference is that USB transfer bypasses the 50 MB limit and requires no internet connection or Amazon account interaction.

For the best results with a complex PDF, convert it to KFX using leafbind first (see Method 4), then transfer the KFX file via USB. KFX files transferred via USB use Kindle's native layout engine — the column detection, footnote linking, and heading structure from the conversion are fully preserved.

Method 4 — Convert to KFX and sideload via leafbind

If you need a PDF to read correctly on Kindle — multi-column layouts, tappable footnote links, navigable chapter structure — converting to KFX before transferring produces the best result. KFX is Kindle's native format; a properly structured KFX file uses the device's full layout engine rather than falling back to a PDF viewer.

leafbind converts PDFs to KFX using coordinate-based text extraction — the same approach that distinguishes left column from right column in a two-column academic paper, rather than reading the text stream in the interleaved order that Send-to-Kindle and Calibre both produce.

How to convert and sideload

Upload your PDF at leafbind.io/convert/pdf-to-kfx
Select KFX as the output format (premium conversion)
Download the converted KFX file
Connect your Kindle via USB and copy the KFX file into the Documents folder
Eject and open the file on your Kindle — it appears in the library under Books

The converted KFX includes a navigable table of contents from detected headings, tappable footnote popups for superscript citations, and correct column ordering for multi-column source PDFs. The conversion report after step 2 shows how many headings were detected and whether any pages required OCR fallback.

Free tier: EPUB output, up to 20 MB, 3 conversions per day, no account required. KFX output is available on premium plans. See pricing →

Common failures and fixes

If Send-to-Kindle isn't working at all — files not arriving, app not sending, files rejected — most problems fall into four categories: unapproved sender address, file size over 50 MB, file format not supported, or Amazon service delays. These are covered in detail in the troubleshooting guide.

Send to Kindle not working: 7 fixes →

The most common failure for new users: sending from an email address that has not been added to the Approved Personal Document E-mail List. Amazon delivers no error for this — the email appears to send normally, but the file never arrives. Fix: add the sending address at amazon.com/mycd → Preferences → Personal Document Settings.

The most common failure for academic users: the file arrives but is not readable. Two-column text is interleaved, footnotes are missing or dumped at the end unlinked. This is not a configuration problem — it is a conversion limitation. The fix is to use Method 4 (KFX sideloading) instead of Send-to-Kindle for those files.

A note on Kindle Scribe and academic PDFs

Kindle Scribe's 10.2-inch screen makes it well-suited for academic reading, but the screen size alone does not solve the conversion quality problems. A two-column PDF sent via Send-to-Kindle to a Scribe produces the same interleaved text output as on a Paperwhite — the conversion happens server-side before the file reaches the device.

For academic use on Kindle Scribe, the recommended workflow is: convert to KFX with leafbind, transfer via USB-C cable. The Scribe's native KFX support handles column-ordered text, footnote popups, and navigable headings correctly — and the annotation features (handwriting, typed notes) work on properly-structured KFX files in ways they do not on PDFs rendered in PDF view mode.

More detail on the Scribe conversion workflow: PDF to KFX for Kindle Scribe →

If you are deciding between the Kindle Scribe and other devices for PDF reading: Kindle Scribe vs reMarkable vs iPad — which is best for PDFs? →

Frequently asked questions

Can I send PDFs to Kindle for free?

Yes. The Send-to-Kindle email method is free for all Amazon account holders. You email your PDF to your Kindle personal document address — found in Amazon Account → Manage Your Content and Devices → Preferences → Personal Document Settings — and it appears in your library. Amazon converts the PDF to Kindle format during delivery. Data charges may apply if your Kindle downloads over mobile network rather than Wi-Fi.

What is the file size limit for Send to Kindle?

Send to Kindle via email accepts files up to 50 MB. Via the Send to Kindle app on iOS and Android, the limit is also 50 MB. USB cable transfers have no size limit — you can copy files of any size directly to the Kindle's Documents folder. If your file exceeds 50 MB, USB transfer is the most practical option.

Can I send EPUB files to Kindle?

Yes. Amazon added native EPUB support in 2022. You can send EPUB files via the Send-to-Kindle email method, the mobile app, or USB cable. EPUB files with DRM (copy protection from commercial ebook stores) cannot be sent — only DRM-free EPUB files are accepted. For USB transfers, EPUB files open directly in the Kindle app without conversion.

Why does my PDF look different after sending to Kindle?

Amazon converts PDFs to Kindle format during delivery, which strips the original layout. Multi-column text gets interleaved line by line, footnotes are detached from citations or dropped, and headings often lose their hierarchy. This affects academic papers, research PDFs, and technical documents the most. For PDFs where layout matters, convert to KFX using leafbind instead — it uses coordinate-based extraction to handle columns and footnotes correctly.

How do I send a PDF to Kindle Scribe specifically?

The same four methods apply to Kindle Scribe: Send-to-Kindle email to your Scribe's personal document address, the Send-to-Kindle app, USB-C cable transfer (copy to the Documents folder), or convert to KFX with leafbind and sideload via USB. For academic PDFs, the KFX sideload method produces the best result on Scribe — native KFX format uses the Scribe's full layout engine with navigable chapters and tappable footnotes.

How do I send a PDF to Kindle from my iPhone?

Install the Send to Kindle app from the App Store. Open any PDF in the Files app or another app, tap Share, then choose Send to Kindle from the share sheet. You will be prompted to select a destination device and whether to convert to Kindle format. The file is delivered to your Kindle library within a few minutes, subject to the 50 MB limit and approved sender list requirements.

Can I transfer a PDF to Kindle without email?

Yes — USB cable transfer requires no email or Amazon account interaction. Connect your Kindle with its USB cable, open the device in File Explorer (Windows) or Finder (Mac), and copy the PDF into the Documents folder. On Windows, the Kindle appears as a removable drive under This PC. The file appears in your library immediately after you safely eject the device.

What file formats can I send to Kindle?

Send-to-Kindle (email and web uploader) currently accepts: PDF, EPUB (DRM-free), DOC/DOCX, RTF, TXT, HTML, PNG, GIF, JPG, BMP. MOBI is no longer accepted — Amazon removed MOBI support in 2022. USB cable accepts: PDF, EPUB, MOBI, AZW3, TXT, and KFX (MOBI still works via USB even though it was dropped from email/app). Amazon's full current list is at amazon.com/sendtokindle.

How long does it take for a file to appear on my Kindle after sending?

Delivery via Send-to-Kindle email or app is usually within a few minutes. Amazon documents that it can take up to 15 minutes. If the file has not appeared after 15 minutes, check your Amazon library at amazon.com/mycd — the file may be in your library but not yet synced to the physical device. Force a sync by toggling Wi-Fi off and on or by restarting the Kindle. USB transfers appear immediately.

Send to Kindle not working →PDF to KFX converter →PDF to KFX for Kindle Scribe →Kindle Scribe vs reMarkable →

Sources

Amazon Send to Kindle — supported file types and web uploader (last verified 2026-05-17)
Amazon Send to Kindle for Email — step-by-step instructions (last verified 2026-05-17)

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Joe Fowler is a developer and technical writer who built leafbind after spending an unreasonable amount of time coaxing academic PDFs into something readable on a Kindle. He writes about PDF structure, ebook formats, and the conversion pipeline at leafbind.io.