LeafPort: Android to Kindle over USB (free beta, testers wanted)

mammutträd · 06-09-2026, 05:22 AM

I'm the dev of LeafPort - a free Android app that sends your own ebooks to a Kindle over USB, straight from your phone. No PC, no cloud, no account. → leafport.app

Plug in, pick books, send. EPUB/KEPUB/Markdown convert to MOBI on-device; nothing's uploaded anywhere.

Kindle-only for now (Kobo next, iOS after), and so far only tested on a small selection of Kindles - which is why I'm here! Paperwhite, Oasis, Scribe, Colorsoft, a 2024 model, an old one? I'd love to know if it works on yours.

Free closed beta on Google Play - PM me the Google email on your phone and I'll add you.

Try it, break it, tell me what you find. I'll read every reply!

Quoth · 06-10-2026, 08:29 AM

Mobi is terrible. Only K1, K2 & DX family need mobi.

azw3 is OK. Works from K3 onwards.

Likely your app only works with ereaders that connect as USB mass storage? Been able to copy to Kindle or Kobo as long as the format was compatible and no DRM since Android 4.x as long as OTG supported and a suitable mini, micro or C adaptor + regular USB A to whatever (on ereader) cable is used via a file manager.

mammutträd · 06-10-2026, 08:48 AM

LeafPort’s sweet spot is the Kindle-specific phone flow: plug in, pick books, send, with no PC/OpenMTP/cloud/account step. That includes the newer MTP Kindles, and also makes the older mass-storage path less fiddly for people who do not want to manage folders by hand.

On formats, LeafPort copies Kindle-ready files through unchanged: AZW/AZW3/MOBI/PDF/TXT. EPUB/KEPUB/Markdown are converted on-device because Kindles do not read EPUB over USB. For the beta we’re using MOBI as a broad sideloading baseline. AZW3/KF8 support is on the roadmap.

mammutträd · 06-10-2026, 02:21 PM

Just a quick update: AZW3 is now supported. ��

I've got the implementation working and initial tests look good. If anyone wants to throw unusual AZW3 files at it, I'd be happy to hear about any issues you find.

06-09-2026, 05:22 AM	#1
mammutträd Junior Member Posts: 3 Karma: 10 Join Date: Jun 2026 Device: kindle	LeafPort: Android to Kindle over USB (free beta, testers wanted) I'm the dev of LeafPort - a free Android app that sends your own ebooks to a Kindle over USB, straight from your phone. No PC, no cloud, no account. → leafport.app Plug in, pick books, send. EPUB/KEPUB/Markdown convert to MOBI on-device; nothing's uploaded anywhere. Kindle-only for now (Kobo next, iOS after), and so far only tested on a small selection of Kindles - which is why I'm here! Paperwhite, Oasis, Scribe, Colorsoft, a 2024 model, an old one? I'd love to know if it works on yours. Free closed beta on Google Play - PM me the Google email on your phone and I'll add you. Try it, break it, tell me what you find. I'll read every reply!

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06-10-2026, 08:29 AM	#2
Quoth Still reading Posts: 15,527 Karma: 114630301 Join Date: Jun 2017 Location: Ireland Device: All 4 Kinds: epub eink, Kindle, android eink, NxtPaper	Mobi is terrible. Only K1, K2 & DX family need mobi. azw3 is OK. Works from K3 onwards. Likely your app only works with ereaders that connect as USB mass storage? Been able to copy to Kindle or Kobo as long as the format was compatible and no DRM since Android 4.x as long as OTG supported and a suitable mini, micro or C adaptor + regular USB A to whatever (on ereader) cable is used via a file manager.

06-10-2026, 08:48 AM	#3
mammutträd Junior Member Posts: 3 Karma: 10 Join Date: Jun 2026 Device: kindle	LeafPort’s sweet spot is the Kindle-specific phone flow: plug in, pick books, send, with no PC/OpenMTP/cloud/account step. That includes the newer MTP Kindles, and also makes the older mass-storage path less fiddly for people who do not want to manage folders by hand. On formats, LeafPort copies Kindle-ready files through unchanged: AZW/AZW3/MOBI/PDF/TXT. EPUB/KEPUB/Markdown are converted on-device because Kindles do not read EPUB over USB. For the beta we’re using MOBI as a broad sideloading baseline. AZW3/KF8 support is on the roadmap.

06-10-2026, 02:21 PM	#4
mammutträd Junior Member Posts: 3 Karma: 10 Join Date: Jun 2026 Device: kindle	Just a quick update: AZW3 is now supported. �� I've got the implementation working and initial tests look good. If anyone wants to throw unusual AZW3 files at it, I'd be happy to hear about any issues you find.