How can we help?
The answers below cover most of what comes in. Anything else — bugs, a book that won’t process, account or billing trouble — email us and you’ll get a human.
Books and uploads
Which formats can I upload?
EPUB, PDF, and plain text, up to 5 MB per file. You can also paste a direct link to a .pdf or .txt file — a link to a web page about a book won’t work, it has to be the file itself. EPUBs have to come through the file picker rather than a link.
Why is my EPUB refused?
Two common reasons: it’s over the size limit (usually because it’s full of illustrations — Tilia only reads the text), or it’s DRM-protected, in which case no app but the store you bought it from can open it.
My book has been “processing” for a while.
A long book takes a minute or two: the whole text is being extracted and every word looked up. If it’s still stuck after that, or it says the processing failed, send us the title and we’ll look at the actual error.
Where does my reading position go?
It’s saved to your account, so signing in on another device continues where you stopped.
Words, cards, and reviews
Why isn’t a word I don’t know in my deck?
Cards are filtered against your vocabulary estimate, so a word can be skipped if the estimate says you know it. Two fixes: long-press the word in the reader and define it — an explicit tap always adds the card, whatever the estimate says — or retake the vocabulary test if your estimate feels too high.
A card shows a different form of the word I tapped.
That’s deliberate. Inflected forms are resolved to their dictionary headword, so tapping “beguiled” studies beguile. The example sentence still comes from where you met it.
I already knew this word.
Dismiss the card and it stops coming back — and it still counts as a word you know, which is what the estimate is for.
When do reviews come back?
On a spaced-repetition schedule: a word you get right waits longer each time, a word you miss returns quickly. Words graduate once they’ve survived three correct reviews and a three-week gap.
Co-reads and friends
How do I invite someone?
Open the co-read and share its invite link, or invite a friend directly in the app. They’ll get the book without it counting against their own library limit while the session runs.
What happens when a co-read ends?
The feed stays readable and your flashcards from the book are untouched. If your library is at the free limit, the shared copy becomes read-only rather than being deleted — make room or upgrade and it unlocks itself.
Can I remove a highlight from a co-read?
You can always delete your own. If you host the session, you can also remove someone else’s from the shared feed — it leaves the room but stays in their own library.
Account and billing
How do I restore a purchase on a new phone?
Sign in with the same Tilia account, open the Pro screen, and choose Restore. Purchases are tied to your App Store or Google Play account, so use the same one you bought with.
How do I cancel?
In your App Store or Google Play subscription settings — app stores don’t let us do it for you. Pro runs until the paid period ends.
How do I delete my account?
From Settings inside the app, or email us from the address you signed up with and we’ll do it within three days. Deletion removes your books, cards, and progress; see the privacy policy for details.
I’m locked out / forgot my password.
Use “Forgot password” on the sign-in screen. If the reset email doesn’t arrive, check spam first, then write to us.
Still stuck?
Email newtonianianlabs@gmail.com with what you were doing, the book title if it’s about a book, and your phone model. Copyright holders should use the copyright policy instead.