KOReader on Kobo: what it is and how to install

KOReader is a free, open-source reading app you can add to a Kobo. It sits alongside the stock reader and gives you far more control over how books look and which formats you can open.

Why people install it

The built-in Kobo reader is fine for most books, but it is fairly locked down. KOReader is built for e-ink screens and gives you fine control that the stock software does not:

Deep typesetting control: margins, line spacing, fonts, and layout, adjusted to your taste.
Fast, no-animation page turns that feel quick even on older Kobo hardware.
Built-in dictionary lookups and reading statistics.
It works with Calibre for managing your library.

If you like tinkering with how a page looks, or you read formats the Kobo does not handle well, KOReader is the usual answer.

Formats it opens

This is a big reason people add it. KOReader opens far more than the stock reader, including:

EPUB, FB2, Mobi, HTML, RTF, DOC, CHM, and plain TXT for reflowable books.
PDF and DjVu, with tools to reflow scanned documents so they are readable on a small screen.
Comic formats like CBZ and CBT, plus ZIP archives of supported files.

How installing it works

You do not replace the Kobo software. KOReader is added as an extra app and launched through a small launcher, so the normal Kobo reader stays exactly as it was. Most people install it using one of the common Kobo add-on tools such as KFMon or NickelMenu, which give you a way to open KOReader from the home screen.

Because the exact steps depend on your Kobo model and firmware, the safest source is the project's own installation guide. The official instructions are kept up to date here: github.com/koreader/koreader, which links to the Kobo install page on their wiki.

KOReader is a well-established project used by a large community, and it does not remove or break the stock reader. As with any add-on you install yourself, it is worth reading the current instructions for your model first, and you can remove it later if it is not for you.

Does it change how you load books?

No. You still put books on the Kobo the same way, over USB or through the cloud. See the guide on putting books on your Kobo. The difference is which app you open them in once they are on the device.

What about kepub?

Kepub is a Kobo-specific format that the stock reader uses for its page tracking. KOReader reads plain epub very well on its own, so if you read mainly in KOReader you do not need kepub. If you switch between KOReader and the stock Kobo reader, converting to kepub still gives you the best result in the stock app.