The Leitner system: flashcards in boxes, explained
TutorAura guide · Updated
The Leitner system is a way of reviewing flashcards using several boxes. Every card starts in box 1. When you get a card right, it moves up a box; when you get it wrong, it goes back to box 1. You review box 1 most often and the higher boxes less often, so you spend your time on the cards you don't know yet.
It was described by the German science journalist Sebastian Leitner in the 1970s and is the idea behind many flashcard apps, including the review boxes in our free flashcard maker.
Key takeaways
- Right answer: the card moves up a box. Wrong: back to box 1.
- Review lower boxes more often than higher boxes.
- It builds spaced repetition into your flashcards automatically.
- Say the answer before you flip the card.
How to set it up
- Make 3 to 5 boxes (envelopes or elastic-banded piles work too).
- Put every new card in box 1.
- In each session, review the boxes that are due. Say or write the answer before turning the card over.
- Correct: move the card up one box. Wrong: move it back to box 1, however high it was.
- A card that passes the top box is learned. Review it again before the exam.
A sample schedule
| Box | Review | What's in it |
|---|---|---|
| 1 | Every session (daily) | New and missed cards |
| 2 | Every 2 to 3 days | Cards right once |
| 3 | Weekly | Cards right twice |
| 4 | Every 2 weeks | Well learned |
| 5 | Before the exam | Mastered |
The exact gaps don't matter much. What matters is that they grow.
Why it works
It combines two of the best-supported study methods. Answering from memory is retrieval practice, and the growing gaps between reviews are spaced practice. A review of hundreds of experiments found that spreading study out beats massing it together for long-term memory (Cepeda et al., 2006).
In one flashcard study, spacing beat cramming for 90% of the students, yet most of them believed cramming had worked better (Kornell, 2009). Spacing feels harder, which is part of why it works. More in spaced repetition.
Making good cards
- One fact per card. "Causes of WW1" is too big; "What does MAIN stand for?" works.
- Ask a question, don't just write a word.
- Use both directions for vocabulary.
- Add a picture where it helps.
See how to make flashcards for more.
Common mistakes
- Moving a missed card down only one box instead of back to box 1.
- Reviewing every box every day, which removes the spacing.
- Flipping the card before you've committed to an answer.
- Letting box 1 grow to hundreds of cards. Add new cards in small batches.
A week with Leitner boxes
Say you start 30 new vocabulary cards on Monday. All 30 go in box 1, and you get 18 right, so they move to box 2. On Tuesday you review only box 1 (the 12 you missed); 8 move up. On Wednesday you review box 1 and box 2 together, and anything you miss drops back to box 1. By the end of the week, most of your time goes on the handful of words that are genuinely hard, which is exactly where it should go.
Frequently asked questions
What happens when a card reaches the last box?
It's well learned, so you only need to see it occasionally. Review the top box before the exam, and move any card you miss back to box 1.
How many boxes should the Leitner system have?
Three to five is common. More boxes give longer gaps for well-known cards; three is enough for a short revision period.
Is the Leitner system the same as spaced repetition?
It's one way of doing spaced repetition. Apps such as Anki use algorithms to set intervals card by card, but the principle is the same: review hard cards often and easy cards rarely.
Can I use the Leitner system online?
Yes. Our free flashcard maker sorts your cards into boxes automatically as you mark them right or wrong, and saves them in your browser.
Sources
- Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin (Cepeda et al., 2006).
- Optimising learning using flashcards: Spacing is more effective than cramming. Applied Cognitive Psychology (Kornell, 2009).
- Improving Students' Learning With Effective Learning Techniques. Psychological Science in the Public Interest (Dunlosky et al., 2013).
Keep reading
Free flashcard maker with spaced repetition
Paste a list to make cards, then study with Leitner boxes so missed cards come back more often.
Spaced repetition: how to remember more by studying less at once
Why spreading study over time beats cramming, and a simple schedule you can start today.
How to make flashcards that actually work
One idea per card, questions not words, both directions, and a spaced review schedule.
Active recall: the study technique that beats rereading
Why testing yourself beats rereading, and five practical ways to do it for any subject.