1
Make a card
Front: a question, a word, or a fact. Back: the answer. That's it.
The classic Leitner method · Since 1972
Remember anything.
Forever.
Learn languages. Memorize facts. Sharpen your memory.
A flashcard system that knows when you'll forget — and shows you the card just before that. No daily grind. No algorithm. Free forever.
Works offline. No sign-up. Native apps coming soon.
What is it?
What is a Leitner Box, really?
It's a flashcard system from 1972 that quietly does one thing: it shows you the right card at the right time. New and tricky cards come back daily. Cards you know stretch out further and further — until they're locked into long-term memory.
You don't pick when. You don't track anything. You just answer what shows up.
Read the full method →How it works
How does it actually work?
Three things. That's the entire system.
2
Answer it
Easy → it climbs to a higher box. Hard → it drops back to box 1 for daily review.
3
Forget about timing
LeitnerBox shows each card exactly when it's due. You just open the app and answer.
Does it work?
Will I actually remember it?
Yes — and there's 140 years of memory science behind it. In 1885, Hermann Ebbinghaus mapped the curve of forgetting: we lose most of what we just learned within a day, unless we review it.
Each spaced review flattens that curve. The Leitner system is one of the simplest ways to apply this — without an opaque algorithm deciding for you. You see the cards. You answer them. The boxes do the rest.
Read the science →How to start
How do I start?
Open the app. Make your first box. The first card takes 30 seconds. Here's what awaits you inside.
Your boxes,
your pace
7 Leitner
levels
Flashcards,
pure focus
Know it,
or don’t
Add cards
fast
Streak, stats,
Pro
Haptic, sound,
your way
Tune every
tap
Ready when you are.
Free forever · No account required · Works offline
Quick answers
Anything else?
Yes. Free forever, no ads, no tracking. There's an optional Pro upgrade ($7.99 one-time) for cloud sync, advanced analytics and 30-day backup history. No subscriptions.
No. Your cards live on your device. You only sign in if you want to sync between devices (Pro feature). Otherwise — open and use, like a notebook.
Anki uses a 4-button confidence rating fed into the SM-2 algorithm. LeitnerBox uses 2 buttons (Know / Don't know) and 7 fixed boxes. The retention difference is small (within 5–10%), but Leitner is dramatically simpler to understand and to trust.
Yes. Everything is stored locally on your device. You can study on a plane, on a subway, anywhere without internet. Pro cloud sync happens automatically when you're back online.
Anything that fits on a flashcard: foreign vocabulary, medical terms, law cases, code syntax, exam material, names and faces, dates. If you can write a question on one side and an answer on the other, LeitnerBox handles the rest.
7 boxes plus a Mastered state. Review intervals: 1, 2, 4, 7, 15, 31, 64 days. The minimum path from new card to Mastered is 124 days of clean answers.