#koreader

This is the wiki that explains step by step and with images how to Jailbreak the kindle and how to install KOReader. Everything is there, just read carefully. You can find your kindle serial number on the "device info" settings.

Even with careful reading I downloaded the wrong KOreader version the first time lol, is not the end of the world.

When you go to the page to get the KOReader files, if you have the same Kindle Oasis as me you need to scroll down till "Assets", click "show all assets" and then download this one "koreader-kindlehf-v2025.04.zip".

If the Installation of the jailbreak seems to not be progressing at some point you probably have to turn off airplane mode at that stage (this seems obvious but this part of the tutorial was a bit confusing on the wiki, at least for me).

The video says that the process takes 10 min, but being honest it took me around 40 because of some mistakes on my part and I spent like 5 hours just deciding what pictures I wanted for the screensavers, so depending on how tech savvy (and obsessive) you are try to set more time aside for this just in case (I spent a big part of my Saturday doing this and it kept me busy while sick in bed with a cold so this was a welcomed entertainment).

To create my covers exactly how I wanted them (filling the entire screen or at the center) I used Photopea (is like photoshop but online, it has ads on the side but in my case I don't care, they need money somehow and I refuse to use Adobe products).

I created a new file with the Kindle Oasis resolution (1680 x 1264px and 300 DPI) and then just pasted the images I wanted there, resized and moved till I was content, and saved them as Jpegs on a folder called "ScreenSavers".

This folder can then be dragged to the kindle when is connected to a computer and KOReader will be able to use it as source for the sleep screen images. This was the result:

Now, I've seen some comments about KOReader not being aesthetically pleasing but I think it comes from the first look we get from it since all the folders there look like this:

KOreader is extremely customizable though, so I just created a folder called "Home" and chose it as the default Home folder. Now every time I click the Home button it takes me to my "Library".

You can display the books in lists, grids, etc., and customize basically all the info you want them to show (or not), how many books appear pear page, if you want to order them by series, author, etc.

You can also create collections.

Honestly, the amount of customization is endless (I was playing with all the menus for a few hours, but now everything is as I wanted it and I can just read and relax).

One thing I love is that you can look up terms or phrases from a book on Wikipedia and they come with images + you can download the Wikipedia articles to read offline later as an epub.

You can also customize what info appears on the cover screen (or remove this). In my case some book names are too long and make a double line so I decided to show just the % I've read on my latest book and the battery.

You have to write the words "read" and "left" yourself, or any text you want to add. The text for what my cover is displaying looks like this:

The progress bar is also fully customizable and you can choose what to display and in what order:

There's a LOT you can do with KOReader in terms of spacing, styling, fonts, etc. Stefan Svartling has many YouTube videos showing what's possible.

Now, how do I get my books into this thing? KOReader can connect with calibre so you can wirelessly send all your books to the Kindle or connect the device to a computer with a cable and drag the books.

Where do I buy books? Calibre comes with a "Get Books" function that allows you to search from different vendors or in the case of Public Domain books it lets you fetch them from places like Project Gutenberg for free.

In my case, I'm getting new books mostly from ebooks.com, they tend to be cheaper there than on Amazon. For example, Howl's Moving Castle by Diana Wynne is 5,49€ on ebooks.com and 10.67€ on Amazon.

Please be aware, a lot of e-books are now sold encrypted with Digital rights management (DRM). This means you can only open them in certain devices and can't copy them to others. You can add plugins to remove the DRM and then send them to KOReader, but this is illegal in some countries, so always check what's the copyright law were you live.

ebooks.com has a DRM-Free (legal) category, so you can search if the book you are looking for is there.

Pros of Jailbreaking the Kindle:

All things mentioned above.

You can still access the Amazon books you had if you exit the KOReader interface.

If something goes a bit wrong you can factory reset the Kindle and it will be practically brand new, then you can re-download your books from your Amazon account.

Cons of Jailbreaking the Kindle:

It doesn't work right now on new devices with the latest firmware.

You void the warranty.

If something goes extremely wrong you could brick the device.

You could get malware if you download resources from untrustworthy websites.