KOReader: Open-Source eBook Reader

Posted by charleshan 3/31/2025

KOReader: Open-Source eBook Reader(github.com)

420 points | 106 commentspage 4

Mossy9 4/1/2025|

When I was figuring out what reader to put in my ancient android 5 tablet (dedicated for offline ebooks) I tried KO, but the UI was way too complex. I've since been happy with Librera, but seeing all this high praise, it seems that I need to revisit KO.

Nice to see there are multiple open source readers going strong!

SheinH 4/1/2025||

Shout out to the developers of KOReader. I love this application so much.

Saves me so much work in having to convert EPUB files on my Kindle. I also love how great it is at handling PDF files and cropping margins out of pages. I don't think I would ever want an e-reader that couldn't run it at this point.

b0dhimind 4/1/2025||

It's like learning to pilot a plane.... manually. Worth learning though and reading some manuals online. Minimal margins maximizing screen real estate, gesture shortcuts for almost anything, great reflow, and so much visual customization at a default level as well as per PDF... as well as having "profiles" to switch across. It's pretty amazing.

Most major miss is more friendly syncing though. Currently only supports Dropbox (WebDAV FTP seems to have issues, even when I used OneDrive key for it which works everyone else) and doesn't actually bidirectionally sync... only downloads. Why can't there be a simple auto-sync from a specific FTP directory including reading positions and such...?!

Also doesn't support Pocket or more popular sync services (only supports Wallabag).

remram 4/2/2025|

It is nothing like learning to pilot a plane. Let's stop pretending that reading 3 paragraphs of texts is insurmountable. You can spend 2 minutes to get acquainted to an app you will use for hundreds of hours, and it's not like you need to know every feature to get started. You won't crash into the ground.

I'm sick of the cult of "intuitive". Intuitive only helps you the first time you ever use an app, and its lack of useful features hurts you forever. It obviously makes sense to optimize for the long run.

boznz 4/1/2025||

Pretty keen to try one day, a quick question for anyone who has installed it is what does it do to the battery life of the device its installed on?

is it the same, better or worse and by how much?

Agraillo 4/1/2025||

With eInk screens it's an interesting story. Because when your page is shown, there is no need for CPU at all for keeping it, so in an ideal world for such devices every page flip is a micro-cycle of waking up from the deep sleep, doing a job and going back to sleep. With such a lifecycle it's even better to measure the battery life not in hours but in page flips. When KOReader supports going to the deep sleep between flips then the difference between it and the bundled software should be small. But if for some reason there's no going to DS between flips, the battery life will drop significantly and back to time units per charge.

dantondwa 4/1/2025|||

On my Paperwhite from 2018, the battery life is better on KOReader than on Amazon’s firmware.

philips 4/1/2025|||

What device? I haven’t noticed an issue on android devices. On my rooted kindle it is a bit less battery but I haven’t measured it.

complexworld 4/1/2025|||

On my Kobo Libra 2 I never noticed a difference.

herboh 4/1/2025||

I installed on a brand new kindle and didn't notice any difference.

rat87 4/1/2025||

How does it compare to the other big foss e-book app, FBReader?

Does the focus on eink mean it's mainly aimed at jail broken eink tablets? Or aimed at phones as well?

presbyterian 4/1/2025|

You don't need to jailbreak, there are many eink tablets that will run it via sideloading (Kobos, for example, and I believe Nooks as well) and eink Android devices (like the BOOX line) that can just install it from F-Droid

GordonS 4/1/2025||

If I installed this ony Kindle, would it sill be able to read all the books I have with DRM? (I've bought lots of ebooks from Amazon over the years)

kristofferR 4/1/2025|

Yeah. You need to remove the DRM first ofc, but thats really easy: https://www.youtube.com/watch?v=5CIFbUIKwDY?t=219

user3939382 4/1/2025||

It’s hideous but it works great, and better that than the reverse right?

If you combine this with a Kobo you have an ereader experience without all the DRM crap.

coolca 4/1/2025||

Once you get used to it, you cannot go back! I would love for a self hosted web interface.

andro_dev 4/1/2025||

KOReader is the best ereader.

_emacsomancer_ 4/1/2025||

And it works on Android too. Even for devices that aren't e-ink, I prefer KOReader to anything else.

Multicomp 4/1/2025||

I prefer Moon Plus Reader because it does not force itself to be full screen.

stuxnet79 4/1/2025|

I've installed KOReader in about 3 devices but I haven't yet cracked how to keep them all in sync - frankly, I don't know how the syncing process works.

I used to think that it syncs up both the books and the reading progress / metadata but when I tried doing it, it didn't seem to work that way. I would love to hear how folks have done this. It's about the only thing left that's keeping me from using KOReader more frequently on all my devices.

thallian 4/1/2025|

The progress sync is separate from how books get onto the various devices (at least as far as I know). Something OPDS capable works well to get the actual files across a network (or calibre via usb). For progress you can use their provided sync server or run your own (the original one gave me enough trouble to write my own implementation).

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