Lantern
support.

Lantern reads standard, DRM-free EPUB files. If your book fails to open, it is most likely protected by DRM. You can remove DRM from books you own using a free tool called Calibre. If the file still won’t open after that, it may be in an unsupported format — try converting it to EPUB in Calibre first, then importing again.

Lantern uses Apple’s on-device translation framework, which supports 19 languages. The first time you use a language pair, your iPhone may need to download the translation model — this is a one-time download handled by iOS in Settings > General > Dictionary & Translation. Once downloaded, everything runs locally with no network connection required.

Translations come from Apple’s machine translation framework. They are contextual and usually good, but they are not perfect — especially with literary prose, idioms, or very long sentences. If you spot a particularly bad one, I’d like to hear about it: drop me an email at lantern@danwaldie.com with the original text and what went wrong.

Your library, reading progress, and saved words all live on your device. If you reset or replace your iPhone, that data is only preserved if you restore from an encrypted device backup (iCloud or Finder). Lantern has no server and no accounts, so there is nothing to sync from our side. We recommend keeping device backups enabled.

In your library, swipe left on any book to reveal the delete option. This removes the book and its reading progress from your device. Gutenberg books can always be re-downloaded; imported EPUBs will need to be imported again from the original file.

No. Lantern is entirely on-device — there are no accounts and no cloud sync. Your library and progress live only on the iPhone where you use the app.

For anything not covered here, email me at lantern@danwaldie.com. I typically respond within a few days. You can also review our privacy policy if your question is about data or privacy.