Key takeaways

Jailbreaking unlocks Kindle software modifications that sidestep Amazon's limitations.
It proves especially valuable for legacy Kindle models losing Amazon's backing.
Starting May 20, eight Kindle variants will lose official support.

Amazon will discontinue technical assistance for select older Kindle devices from May 20 onward, yet owners need not discard them. Models and Fire tablets from before 2013 will miss future software updates from Amazon, prompting users to seek fresh options for e-reading.

A favored method to prolong a Kindle's utility involves jailbreaking. This circumvents key Amazon constraints, enabling enhanced interface tweaks, hidden settings access, and installation of rival reading apps.

Those pursuing jailbreaks on legacy Kindles often add KOReader, KUAL Launcher, custom fonts, and screensavers - installations I recently tried on my dated Paperwhite. Below, I detail the jailbreak process on my older Kindle, the features it unlocked, and key insights gained.

Jailbreaking a Legacy Kindle: Step-by-Step

Disclaimer: We do not endorse using jailbroken devices for illegal purposes. Users must adhere to laws on digital rights management and hardware alterations. Consult legal counsel if unsure.

Check model and firmware: Access Settings on your Kindle, select Device Options, then Device Info. Note the model, such as "Kindle Paperwhite (10th generation)" and firmware like 5.18.1 on mine.
Block auto-updates: Wireless updates have long nullified jailbreaks and custom apps, so many disable Wi-Fi or enable permanent airplane mode.
Obtain jailbreak package: Risks arise here, leading me to favor USB book transfers over full jailbreaks. Jailbreak files appear on forums and boards, but untrusted origins pose malware threats.
Link via USB: Attach your Kindle to a PC with a USB cable, then place the .bin jailbreak file in its root directory. Trigger an update to apply it.
Add hotfixes or certs: Jailbreaks typically need these to evade Amazon's unsigned app blocks. Per instructions, copy an MKK file to the device folder.
Set up KUAL: This launcher provides a menu interface for jailbroken Kindles.
Deploy KOReader: A prime open-source reader for modded Kindles, it supports EPUB and more, with superior PDF handling, typography options, gestures, file browsing, and swift library navigation.

Jailbreak Downsides on Kindle

Testing KOReader on my Paperwhite revealed jailbreaking pitfalls worth noting.

Jailbreaking exposes software to instability, from app glitches to total failures, given the unofficial code. I saw lags and freezes post-reboot or low battery.

Battery drain intensified too, as KOReader lacks the efficiency of Amazon's OS, shortening runtime during heavy use.

Safer Book Loading for Older Kindles

Legacy Kindles remain viable e-readers sans jailbreak; simply sideload via USB from a PC - my preferred, straightforward route.

Kindles accept EPUB, PDF, RTF, DOC, DOCX, HTML, HTM, JPG, JPEG, GIF, PNG, or BMP files directly.

USB connection: Link your Kindle to a computer like any drive.
Locate drive: Use Finder (Mac) or Explorer (Windows) to access the Kindle folder.
Place files: Drop ebooks into the Documents subfolder.
Safely eject: Unmount before unplugging.

Final Assessment

Jailbreaking my 2018 Paperwhite succeeded, but I favor USB sideloading for ebooks. Jailbreaks risk bricking devices, and reliable file sources are scarce and hazardous, making them unadvisable for most.