Leitner System Flashcards: The 5-Box Method Explained
Leitner system flashcards sort your cards into numbered boxes based on how well you know them. Get a card right, it moves up a box and you see it less often. Get it wrong, it goes back to Box 1 and you see it every day. That's the whole trick: you spend your time on the cards you don't know, not the ones you do.
If flashcards feel like they're not working because nothing sticks, IQ Tester can show whether memory or focus is your weak spot and give you a short daily drill. Find my weak spots
What the Leitner system is
The Leitner system is a flashcard study method created by Sebastian Leitner, a German science journalist, who described it in his 1972 book So lernt man lernen ("How to learn to learn"). It's one of the simplest forms of spaced repetition, the idea that reviewing information at growing intervals helps you remember it for longer.
Before apps did the scheduling for you, this was the scheduling. A shoebox, some dividers, and a rule: right answers move forward, wrong answers go back to the start.
Why it still slaps in 2026:
- It's free and works offline.
- You physically see your progress (Box 5 filling up hits different).
- It forces honest answers. No "eh, I basically knew that" button.
The 5-box schedule
Here's a standard Leitner box schedule. Tweak the gaps to fit your exam dates, but keep the pattern: each box gets reviewed less often than the one before.
| Box | Review how often | What's in it |
|---|---|---|
| Box 1 | Every day | New cards and cards you got wrong |
| Box 2 | Every 2 days | Cards you got right once |
| Box 3 | Every 4 days | Getting there |
| Box 4 | Once a week | Mostly solid |
| Box 5 | Every 2 weeks | Nearly locked in |
The two rules:
- Correct: move the card up one box.
- Wrong: move it back to Box 1. Not down one box. All the way back.
Some people use a gentler version where a wrong card only drops one box. That's fine for huge decks, but the classic "back to Box 1" rule is what makes the Leitner system study method so effective at killing weak cards.
When a card survives Box 5, retire it to a "done" pile and check that pile once before the exam.
Set it up with paper cards
What you need
- Index cards (or cue cards, as a lot of UK and Canadian students call them)
- A shoebox or 5 envelopes, labeled 1 to 5
- A pen and 20 minutes
Writing the cards
- One fact per card. "What does the mitochondria do?" not "Everything about cells."
- Question on the front, short answer on the back.
- Use your own words. Copying textbook sentences word for word makes cards that look right but don't test much.
A 7-day paper timetable
- Day 1: Box 1
- Day 2: Box 1, Box 2
- Day 3: Box 1
- Day 4: Box 1, Box 2
- Day 5: Box 1, Box 3
- Day 6: Box 1, Box 2
- Day 7: Box 1, Box 4
Pin that on your wall or save it as a note. That's your Leitner method PDF, minus the PDF.
The annoying part of paper Leitner is tracking: which box is due, which cards keep bouncing back, and whether you're actually improving. IQ Tester can't sort your flashcards, but it does track the bigger picture of how you reason. Its guides spot weak areas like memory, focus or verbal and give you a short daily drill to work on. Find my weak spots
Leitner in apps (Leitner system online)
If you want a Leitner system app instead of a shoebox, you have options:
- Flashcard apps with a "Leitner" mode. Several apps literally call their feature Leitner boxes. Search your app store for "Leitner" and pick one with good reviews and offline mode.
- Anki. Doesn't use boxes, but does the same job with a smarter algorithm (more below).
- Quizlet. Its Learn mode repeats cards you miss, which feels similar, though it isn't a strict Leitner schedule.
- DIY in Notion or Google Sheets. A column for "box" and a column for "next review date." Surprisingly effective if you like spreadsheets.
Paper plus app combo: write the cards on paper first (writing by hand helps you think about them), then move the stubborn Box 1 cards into an app so you can drill them on the bus.
Leitner vs Anki
This is the question most people on Reddit ask. Short answer: Anki is Leitner with a much smarter brain.
| Leitner system | Anki | |
|---|---|---|
| Scheduling | Fixed boxes, fixed intervals | Algorithm adjusts each card's interval |
| Wrong answer | Back to Box 1 | Card resets to short intervals |
| Effort to set up | Low, just boxes | Medium, some settings to learn |
| Cost | Price of index cards | Free on desktop and Android; paid iOS app |
| Works offline | Always | Yes |
| Feels satisfying | Very (physical boxes) | Depends on you |
| Best for | Smaller decks, younger students, anyone who likes paper | Big decks, languages, med school, long-term |
Anki's default scheduler comes from the SM-2 family of algorithms, and newer versions also offer an optional scheduler called FSRS. Both give each card its own interval based on how you rate it, instead of moving whole boxes on a fixed timetable.
Which should you pick? For a GCSE or AP class with a few hundred cards, Leitner is plenty. For thousands of cards (med school, languages), use Anki. For a full breakdown of the apps, check Anki vs Quizlet.
Common Leitner mistakes
- Being nice to yourself. If you hesitated or half-knew it, it's wrong. Back to Box 1.
- Cards that are too big. A card with a paragraph on the back will never leave Box 1.
- Skipping Box 1 days. Box 1 is the whole engine. Miss it and the system collapses.
- Adding too many new cards at once. Twenty new cards a day is manageable. Two hundred is a Box 1 avalanche.
- Only reading the front and "feeling" the answer. Say it or write it before you flip.
- Never retiring cards. Box 5 cards you've nailed twice can take a break.
If you need cards locked in fast, pair this with the tips in how to memorize flashcards quickly. And to set your gaps precisely, the spaced repetition schedule has copy-paste intervals.
Figure out what's slowing your flashcards down
Leitner system flashcards show you which cards are hard. They don't tell you why your brain keeps dropping them. IQ Tester gives you 20 untimed questions across number series, verbal analogy, logic and pattern, and the free result shows your score band and three of your four category strengths. From there, its guides give you a short daily drill for your weak spot.
FAQ
How does the Leitner system work?
You sort flashcards into numbered boxes. Cards you get right move up to a box you review less often, and cards you get wrong go back to Box 1, which you review every day. Over time, your study time naturally goes to the cards you don't know.
What is the best Leitner box schedule?
A common one is Box 1 daily, Box 2 every 2 days, Box 3 every 4 days, Box 4 weekly and Box 5 every 2 weeks. If your exam is soon, squeeze the gaps; if it's months away, stretch them.
Is the Leitner system better than Anki?
Not better, but simpler. Anki adjusts every card's interval individually, which is more efficient for huge decks. Leitner is easier to start, works on paper, and is plenty for most school subjects.
Is there a Leitner system app?
Yes, several flashcard apps offer a "Leitner" mode, and Anki does a similar job with its own algorithm. You can also build a Leitner system online in a spreadsheet with a column for the box number and the next review date.
Can I use the Leitner system for language learning?
Absolutely. It's great for vocab: one word per card, the target language on one side and your language on the other. Review both directions so you can recognize and produce the word.