I really like that this exists, but I found the menus and UI to be rather non-intuitive. My main use case was to sync reading progress between my Kobo and my iPhone. I was able to do this using KOReader on the Kobo & the Readest app[1] on iPhone (also open source).

Ultimately I decided to get rid of KOReader because it felt a bit laggy. The gestures (eg: swiping up on the left side to increase frontlight brightness) didn't work well either.

I eneded up writing my own software to sync progress from Kobo to a KOReader Sync server[2] which my Readest app also connects to (love that unlike the Kindle, the Kobo is quite an open system). You can even set it up so you can SSH into it[3].

[1] https://github.com/readest/readest [2] https://github.com/koreader/koreader-sync-server [3] https://www.mobileread.com/forums/showthread.php?t=254214

I installed it on my Amazon Kindle and I couldn't be happier. It shows once again that free software is superior to proprietary software. Free software grows slowly to make users happier and not to attract them with useless features to extract more value from them. Congratulations for this great piece of software.

You can use the regular Kindle viewer once you jailbroke your kindle, but KOReader has native epub and pdf support so you don't have to use a converter when uploading your books.

I did find it hard to get the bezels to be even and it still doesn't always format well depending on the book. I still kind of prefer the default viewer.

I use this plugin in KOReader which lets you download books from Z-Library within KOReader.

https://github.com/ZlibraryKO/zlibrary.koplugin

Another cool thing is you can use custom fonts and dictionaries. I use the OED short version and the Wikipedia one. There's built in ones that it can download but pirated ones like OED you have to upload yourself.

Unfortunately on MacOS it seems you have to use Amazon's app to access the filesystem.

Edit:

They changed it on the newer Kindle which I have.

There's open source alternatives to the send to kindle app.

Interesting. I generally hate proprietary software, but I've actually been really satisfied with the kindle UI. I don't use the store at all, simply email epubs to it directly. (I usually only move 1-5 books max at a given time, so this process feels really simple to me). The only adjustments I need are the text size and front light, battery life is amazing. I'm guessing this would be really useful if I had advanced needs, but for just reading epubs, kindle is a really good UI.

KOReader is my jam! With its reflow for PDFs, I've used it on my Kindle Oasis 2 to read everything for my undergrad and graduate degree. Some years ago now, I wrote a script that converts the annotations to Obsidian [0], and then another little script to automatically keep my "Articles" folders in sync between the Kindle and my laptop.

Very grateful for this software!

[0]: https://github.com/simonpacis/kohico

Great piece of software. Jailbroken my Kindle when the UI was becoming way too slow, then discovered Rakuyomi [1] and that alone is worth the jump, especially with plugins like SimpleUI to make the UX better

[1] https://github.com/tachibana-shin/rakuyomi

Lots of nice features but the UX and UI are so painful that it's not worth jumping from the stock kobo reader for me.

It's nice to have another option though and if the UX improves one day maybe I'll use it as my main reader.

EXTREMELY confusing UI, but when you get used to it, nothing really comes close in terms of customisability and features.

Seriously, takes ages to find specific settings for the first few times.

If you use a Kindle, you have to jailbreak it first before installing it. There's definitely been some improvements with user experience at least with apps since I first jailbroke it. There's like an appstore with games and KOReader that I use.

This is the guide I used and it's up to date.

https://kindlemodding.org/

I have one of those Android e-books and it's nice to find good software.

Anyways I just wanted to read using the least possible resources so I'm just using a simple file manager and mupdf (in which KOreader is based). mupdf may be simple, but it's amazing.

I set up KOReader with a jailbroken Kindle. DammitJeff has a good video introducing the topic. UI is definitely awkward, but it is awesome and pretty "hands off" when set up. It also has built-in support for OPDS so downloads from places like "Project Gutenberg" are a breeze. Also, if you are a homelabber with stuff like Calibre & Calibre Sync, it all works as you'd expect.

I have this on my Amazon Kindle and I freaking LOVE it!

Paired with BookOrbit [0] and using plugins like BookShelf, BookEnds, and KOAssistant I have the best reading setup ever.

The speed of this on my Kindle is _insane_ compared to the stock software. I'm not talking about page turning, that was fine on both, but navigating menus is way faster.

It was a little finicky to configure but once I got a feel for it I didn't have a problem and 15 books read later since I installed it a few months ago and I never touch the settings.

My favorite plugins:

BookShelf: Best UI for viewing my books by author/series/etc IMHO. Much better than the Kindle default UI and much snappier

BookEnds: Configure the header and footer of each page to show what info you care about most. There are community configs you can test out easily and download right on your kindle if you like them

KOAssistant: highlight some text and throw it at an LLM with a provided prompt or your custom one. This was invaluable when reading the Hornblower series which used a lot of older english words/phrasing as well as nautical terms (which I'm completely unfamiliar with). I enjoyed the books way more since I could figure it out inside my kindle instead of constantly having to pick up my phone to look up a phrase.

BookOrbit: It provides a plugin for KOReader that syncs your progress, annotations, etc.

KOReader is table stakes for any e-reader I might consider. If my Kindle died tomorrow I'd have a Kobo or similar on it's way to me within hours. I won't use any reader that doesn't support KOReader after using it for these last few months.

[0] https://bookorbit.app/

Previous discussions:

31-mar-2025 https://news.ycombinator.com/item?id=43539103 106 comments

10-apr-2024 https://news.ycombinator.com/item?id=39996947 33 comments

Does it have Kindle X-Ray like features, like integration with Wikipedia or possibly integration with AI for contextual information?

I tried but the whole process is a miserable experience between the stale blog posts and the dead links…

And then the UX… great project but could use a systems guy used to jailbreaking installations and a UX designer

Edit: for kobo at least

It's a great reader app, but as a reader of Japanese light novels it's sadly not fit for my personal purposes - last I checked vertical text is only possible in a really, _really_ hacky way (using a font that is turned sideways), and dictionary support for Japanese (or, say, Finnish with its complex lemmatization) is lacking behind browser extensions such as Yomitan, or mobile apps like Hoshi Reader that have Yomitan dictionary support.

I don't think KOReader handles fixed-size epubs terribly well too, and most of my manga (usually bought on Rakuten Kobo) comes in that format.

For reading English or native language books on non-Android e-readers it's a godsend.

I am using koreader on my ereader and KOreader has a native support for https://wallabag.org/. They are both fantastic opensource projects, whenever I like to read a blog post I am sending them to my wallabag and therefore I can easily have them on my ereader too.

Also the fact that you can install different plugin on KOreader and customize it in a way you like is fantastic. for example just check:

- https://github.com/doctorhetfield-cmd/simpleui.koplugin - https://github.com/AndyHazz/bookshelf.koplugin

Or with Lua you can develop your own plugin for that. to people who wanted to jailbreak their Kindle I can recommend these two links:

- https://kindlemodding.org/ - https://www.youtube.com/watch?v=Qtk7ERwlIAk

All in all I am supper happy with KOreader and can't imagine to use anything else

I have a kobo ebook with [plato](https://github.com/baskerville/plato), it includes koreader but I found the built in mupdf much more intuitive and elegant.

For anyone with a Kobo who only wants to be able to sync with calibre-web without installing anything on your device, here's a link to instructions:

https://jccpalmer.com/posts/setting-up-kobo-sync-with-calibr...

I'm not associate with this person, just know that these instructions worked for me.

I love KOReader on Android, but unfortunately it requires granting permission to manage all files on the device. I would prefer if it used the approach most apps use, which is to select a folder on the device that it can access. Then I can move all my books into that directory and KOReader would not have access to all of the data on my phone.

I have it on my Kobo, it's really good ! I use it with Wallabag, I can save articles on my desktop and sync it before leaving for work, really nice.

I absolutely love KOReader on my Boox Go 10.3!

It has super useful features like the semi-auto-cropping which removes margins in PDFs (like papers or books), including unnecessary things like page numbers or similar, so that you can really maximize the size of the core content. It also has a nice chapter overview and other useful things!

Truly one of the best pieces of software I have used so far.

Any macOS builds out there? I would really like to have one app that can open both ePubs and pdfs.

Don’t need the library feature to manage books like Books.app, just need a light and reliable reader.

If you have a newer Kindle and some hacking skills, consider looking for new Kindle jailbreak methods. The existing jailbreak methods don't work on newer firmwares. ( See https://kindlemodding.org/kindle-models.html )

I finally installed this on my Kobo Libra 2. The UX is clunky but overall it works great. Very fast. Don’t need KEPUBS anymore as epubs render just as fast, where as that’s not the case on the stock software.

I finally got around to installing it as I got an xteink x3 and wanted to have cross device syncing back to my Grimmory server. Works great with OPDS and KOSync.

Although I miss using the native kobo sync where I could just add a book to my virtual shelf and have it auto sync to my device. OPDS seems very rudimentary in comparison, but it works nonetheless.

No Windows? Is it a political choice or is there a technical limitation?

KOReader is so much better, including in how it renders typography and does typesetting than what ships on Kobo devices by default, it's sort of wild.

I actually made a mod to try to upgrade Kobo's built-in reader so it's more correct, i.e. more faithful to how KOReader renders text. Sharing it here since it may be interesting for anyone with Kobo e-readers: https://github.com/nicoverbruggen/NickelTypeFix

I installed this the moment I got my Kobo Libra H2O. Mostly read fiction from the 1800s and early 1900s and I did not want to fight whatever proprietary software the reader came with (Kobo is probably better than the Kindle for this, but I never tried it!)

I have a problem with epubs though. This need to support every single thing under the sun makes the pipeline exceedingly complex. All you need for a vast majority of fiction is:

- headings

- paras

- emphasis (bold/italic)

- block quotes

Add simple "image" syntax to it to display maps etc from detective stories

Basically a ruthlessly cut down version of markdown.

The mini-readers from Xteink came in at the right time for such experimentation.

It took me some time to know my way around it, but wow. I have it configured with some plugins, like zen ui and bookshelf. I Also use BookOrbit to sync reading progress and annotations between devices. Loving it.

I installed this because I wanted the sqlite database that track when I'm turning each page

KOReader is awesome and it's my go to for most e-reader reading. I've recently been trying out Plato (https://github.com/baskerville/plato) as well and it has a really nice experience for reading PDFs. It crops the margins and pages through the PDF in chunks nicely.

So good. I've built a plugin for it to allow me download books from my Jellyfin server on my Kindle 3 Keyboard (from 2010!). Was lovely for develop for and the wide compatibility of KOReader has made it a great investment.

I use KOReader on everything except e-ink devices.

Linux desktop. MacOS laptop. Android tablets. Android phones.

Where-ever I am, I can pick up a device and continue reading from where I left off. I have the same config everywhere (it would be nice to be able to distribute that) for gestures and taps. I use the same font everywhere (TeX Gyre Pagella, which is a Palatino clone.)

Customization begets comfort.

Did anyone made a comparison across different devices for running this? I am curious on what is the best device today to run it, and also the best when accounting for cost of the device too.

Koreader rocks indeed

I use it since years on my PocketBook Touch HD 3. I especially like the statistics. You might not care about them, but I find them very interesting.

I love KOReader! I use it on my Kobo Clara Colour with Calibre. Love Wikipedia lookup, customization options, and the fact that wifi is off by default.

I installed it and I use Calibre to send books over wifi. Simple and sweet setup.

FWIW not only it is in itself nice but it evens has plugin system. Consider extending it and sharing back with the community!

My wish is to see ebooks become first class citizens on all digital devices. Apple has a native ebook reader built in to their devices. It's cumbersome and bloated, but it's there. No web browser except Yandex has built in ebook support, even though it would be the easiest thing in the world. Android, Linux and Windows have no built-in ebook reader, as far as I know.

Murasaki [1] is the most performant and sleek ebook reader you can get for MacOS currently. It's magnificent, but the creator has regionally limited who can get it, unfortunately.

[1] https://genjiapp.com/mac/murasaki/index_en.html

Amazing software. Makes a 10 year old Kindle of the best electronics I own.

I installed it on my Kobo to have the syncing from Calibre. Works perfectly, no complaints.

Use it both on my phone and on an eink Android tablet. Love it, especially the dark mode.

It seems there's a native dictionary. How does it fare?

The PDF support is just the right thing to have.

See also this discussion from earlier today, which might have prompted this submission: https://news.ycombinator.com/item?id=49094189

It really does rock.

Thank you for this

KOREA!