KoboPatch WebUI: customization (NickelMenu, KOReader) and patching via your browser

[MrSilverstrike]

Hi all. A while back I shared an early version of a web UI I built for applying kobopatch patches. Since then it's grown a fair bit and expanded in scope, so I figured it was worth a dedicated thread.

It's an open-source web app that lets you customise your Kobo without needing to install anything on your computer. Everything runs in the browser, and there are two modes:

1. NickelMenu mode: the safer option. Installs my NickelMenu fork on any supported Kobo, either stock or with a curated preset (custom menus, Readerly fonts, screensaver images, simplified tabs/home screen, and optionally KOReader), all in a single step. Can also uninstall NickelMenu. (My NickelMenu fork is used here in order to enable the simplified home screen functionality.)
2. Custom patches mode: lets you pick which community patches you want to apply to your firmware. More flexible, but a bit more experimental, and you'll need to re-run it after each Kobo software update. Powered by a WASM build of kobopatch that runs directly in your browser. Also offers a restore original firmware option if you want to undo patches.

HOW TO USE IT

The easiest way to try it is to visit the website I set up for it. There's also a video with a demo and chapter markers if you want to see it in action first, and a blog post with more background.

SOURCE CODE

You can find the source code on GitHub at github.com/nicoverbruggen/kobopatch-webui (MIT licensed), so you can also clone and run it locally if you want to. I've made sure all of the functionality is properly tested, and I try to get support for the latest updates sorted out as quickly as possible.

DEVICE & BROWSER SUPPORT

For NickelMenu: any Kobo released in 2025 or earlier, running software 4.6 and above (but not 5.x). Uses my fork of NickelMenu. Changes stick around across system updates, as long as NickelMenu itself stays compatible.

For custom patches:

• Software 4.45.x: Kobo Libra Colour, Clara Colour, Clara BW
• Software 4.38.x: Clara 2E, Libra 2, Elipsa 2E, Sage, Elipsa

If your browser supports the File System Access API (Google Chrome, Microsoft Edge, Opera, Arc), the app can detect a connected Kobo automatically and write patches straight to the device. On Firefox and Safari, or on Brave (which disables the API by default for privacy reasons), you'll get a manual flow instead: pick your model and software version, get a ZIP, copy it over yourself.

CREDITS

Big thanks to the following folks:

• pgaskin (geek1011), for kobopatch and NickelMenu, which this app is built on top of.
• JSWolf, for maintaining the 4.45 patch set this app ships with, and the earlier patch sets it builds on.
• jackie-w, Semwize, aardvark, and DNSB, for their patch contributions over the years.
• The wider community here for bug reports, testing, and the reverse-engineering work that makes all of this possible.
• The KOReader team, for the reader that's bundled as an optional install.

If I've missed someone who should be credited here, let me know and I'll fix it.

Obviously, this is not affiliated with Rakuten/Kobo. Patching modifies system files and voids your warranty, and software 5.x is not supported.

I've tested on my own Clara BW and Libra Colour, but the patch set covers more models than that, so let me know if you hit anything weird on the other ones.

FEEDBACK?

If you have any feedback or want to report a bug, feel free to do so here or on GitHub. There's still some stuff I want to do (like make patches editable in the browser, as sometimes you may want to make manual adjustments) but for now I think it's good enough to share!