Spaced Repetition App for Japanese: How to Pick One

A spaced repetition app for Japanese shows you a word right before you would forget it, then stretches the gap each time you remember it. That timing is the whole idea: review a word when it is fading but not gone, and your memory of it grows stronger with less total effort.

These apps handle the scheduling for you. You just answer honestly, and the app decides which words to show today, which to push to next week, and which to hold for a month. Below is a plain guide to how it works, how popular apps compare, and how to build a review habit that actually sticks.

What a spaced repetition app for Japanese actually does

At its heart, the app keeps a deck of cards. Each card holds one piece of Japanese: a vocabulary word, a kanji, a grammar point, or a full sentence. You see one side, try to recall the other, and tell the app how it went.

Behind the scenes it does three jobs for you:

• It picks what to review today. You see only the cards that are due, not the whole deck.
• It sets the next gap. Remember a word easily, and the gap grows. Struggle, and the word returns soon.
• It keeps the load steady. Good apps spread reviews out so you are not buried after a few weeks.

This matters most for Japanese because there is so much to hold in memory: two kana sets, thousands of kanji, and a large vocabulary. Smart timing means your minutes go to the words you find hard, not the ones you already know cold.

How spaced repetition works, in plain words

Your brain forgets new things on a curve. You learn a word today, and within a day or two much of it slips away unless you meet it again. This pattern, where memory fades fast at first and then levels off, is the forgetting curve.

Spaced repetition works with that curve instead of against it. Here is the simple version:

1. You learn a new word.
2. You review it a short time later, while it is still a little fresh.
3. Each time you remember it, you wait longer before the next review.
4. Each successful review makes the memory last longer, so the next gap can be wider.

The sweet spot is to see a word when it is foggy but not fully forgotten. Recall at that moment is a small effort, and that effort is what locks the word in. If you review too early, you waste time on words you already know. Too late, and you are relearning from scratch. The app aims for the middle for every single card, which is something no paper flashcard stack can do.

When you forget a word, that is not a failure. The app simply brings it back sooner and shortens its gaps. Forgetting a little is part of how the method finds the right schedule for you.

What the review intervals look like (with a simple table)

Most guides describe intervals in prose, which can feel vague. Here is a simple picture of how the gaps tend to grow for a word you keep remembering. Exact numbers vary by app and by how you grade each card, so treat this as the shape of the idea, not a fixed rule.

Review number	Roughly when you see the card again	What it feels like
1 (new)	The same day	Just learned it
2	The next day	Still fresh, easy to recall
3	A few days later	Needs a small effort
4	About a week later	A real test of memory
5	A few weeks later	Mostly solid
6	A month or more	Feels almost automatic
7+	Several months	Long-term memory

Two things are worth noticing. First, the early gaps are close together, then they widen quickly. Second, if you forget a card at any step, its gap shrinks and it climbs the ladder again. That is the method doing its job, giving hard words more attention and easy words less.

You do not need to calculate any of this. Modern apps run the math for you with a built-in scheduler, sometimes called smart reviews. Your only job is to show up and answer honestly.

The scheduler behind the app: SM-2 and FSRS

Every spaced repetition app uses a scheduler, the part that decides each card’s next gap. You never see it, but it shapes how efficient your reviews feel.

For years the common one was SM-2, an algorithm from the 1980s that powers classic Anki and many apps built on it. It works well and has taught millions of people. It sets each card’s gap from a few fixed numbers, so it treats most cards with the same broad rules.

A newer option is FSRS, the Free Spaced Repetition Scheduler. It is open source, built on a model of how memory fades, and it became a built-in option in recent versions of Anki. Instead of fixed steps, it estimates how likely you are to recall each card on a given day and places the review near a target you choose, often around a 90 percent chance of remembering. In practice that often means fewer reviews for the same retention, because the timing fits your real memory more closely.

Neither is a wrong choice, and you do not have to think about any of this to learn. SM-2 is proven and simple; FSRS is newer and adapts more tightly to each card. The useful thing to know is that an adaptive scheduler can save you review time, so it is worth turning on FSRS if your app offers it, or picking an app whose smart reviews already adapt this way. Kana Conbini, for example, uses FSRS for its smart reviews, across both vocabulary and handwriting.

Popular spaced repetition apps for Japanese, compared

Several apps use spaced repetition well, and each has a different focus. There is no single right one; the best fit depends on your goal, your budget, and how much setup you enjoy. Here is a side-by-side look.

App	Main focus	Platforms	Free tier	Best for
Anki	Anything you put on a card	Desktop, web, Android, iPhone	Free except a one-time paid iPhone app	Learners who want full control and custom decks
WaniKani	Kanji and related vocabulary	Web, with community mobile apps	First levels free, then subscription	A guided, ordered path through kanji
Kana Conbini	Kana, kanji, and vocabulary	iPhone, Android	Free to start, optional one-time packs	Beginners who want reading and handwriting in one place
Renshuu	Vocabulary, kanji, and grammar	Web, iPhone, Android	Generous free tier	Broad coverage across many JLPT levels
Bunpro	Grammar, with vocabulary	Web, iPhone, Android	Limited free trial, then subscription	Working through grammar in order

A few honest notes. Anki is the most flexible and free on most devices, though it asks you to build or download decks yourself, which some people love and others find fiddly. WaniKani removes all setup by giving you a fixed order, in exchange for a subscription once you pass the early free levels. The others sit between those poles. Try one for a couple of weeks before you commit, since the app you actually open every day beats the one that looks best on paper. If your main goal is kanji, our roundup of Duolingo alternatives for kanji compares several of these same apps from that angle.

Anki versus WaniKani: which feels right for you

This is the most common matchup, and the two apps feel very different in daily use. Neither is better overall. They suit different temperaments.

Anki hands you an empty, powerful tool. You choose your decks, edit cards, and tune the settings. That freedom is its strength and its cost: you can build exactly the study you want, but you have to set it up. It is free on desktop, web, and Android, and a one-time paid app on iPhone.

WaniKani hands you a path. It teaches kanji and vocabulary in a set order using radicals, mnemonics, and timed reviews, so you never decide what comes next. That structure is its strength and its limit: it is smooth and guided, but you follow its order and its scope, and it is a paid subscription after the first levels.

A simple way to choose:

• If you like tinkering and want total control, lean Anki.
• If you want a guided kanji track and do not mind a subscription, lean WaniKani.
• If you want kana, kanji, and vocabulary in one place with no setup, a ready-made app like Kana Conbini may fit.

Apps for vocabulary, kanji, grammar, and sentences

Most listicles cover one type of study. In practice you will want different cards for different parts of Japanese, and the same spaced-repetition timing works for all of them.

• Vocabulary. The classic use. One side shows the word, the other shows the reading and meaning. Native audio on each word helps your ears as well as your eyes.
• Kanji. Cards can drill readings, meanings, and example words. Some apps go further and let you practice writing each character by hand in the correct stroke order, which builds a different kind of memory than reading alone.
• Grammar. You can review grammar points as cards, often with a sample sentence that shows the pattern in use. Apps like Bunpro and Renshuu lean into this.
• Sentences. Whole example sentences on a card show how words and grammar fit together, and they train you to read at natural speed rather than one word at a time.

You do not need a separate app for each. Several apps mix these card types, and you can keep one deck for words and another for sentences inside the same tool. Start with vocabulary and kanji, then add grammar and sentences once your daily reviews feel steady. If you are at beginner level, our guide to choosing a JLPT N5 vocabulary app is a good companion to this one.

Free options and what you get for free

You can practice spaced repetition for Japanese without paying anything to start. Here is what the free side usually looks like.

App	What is free	What costs money
Anki	Desktop, web, and Android, fully featured	A one-time purchase for the iPhone app
WaniKani	The first few levels	A subscription to continue
Renshuu	A large free tier with daily study	An optional upgrade for extra features
Kana Conbini	Free to start with the full vocabulary range and reading game	An optional one-time pack for unlimited daily handwriting

A free tier is a real starting point, not just a teaser. Anki alone can carry you for years at no cost on most devices. If an app limits something in the free tier, it is usually the number of daily reviews or a specific feature, not your ability to learn. Begin free, and pay only once you know the app fits your routine.

If you would rather practice on paper before committing to any app, our free printable Japanese writing practice sheets give you a no-account way to start with kana and kanji today.

How to build a daily review habit that sticks

The best app is the one you open every day. Spaced repetition only works if you keep showing up, so the habit matters more than the tool. Here is what helps.

1. Start small. Add five to ten new cards a day, not fifty. Every new card becomes future reviews, so a small intake keeps tomorrow manageable.
2. Tie reviews to an existing habit. Do them with your morning coffee, on the train, or right before bed. Attaching reviews to something you already do makes them automatic.
3. Clear today before adding more. Finish your due cards first, then add new ones only if you have time and energy. This stops the pile from snowballing.
4. Keep sessions short. Ten to twenty minutes is plenty. Short and daily beats long and rare.
5. Forgive missed days. If you skip a day, just clear a small batch when you return and lower your new-card limit for a day or two. The schedule recovers on its own.

A streak is a tool, not a master. The goal is steady review over months, not a perfect record. If a missed day makes you want to quit, do five cards and call it a win.

Recognition reviews versus writing reviews, and why both help

When you review, you can practice in two ways, and each builds a different strength. Neither is the one correct method; they fit together.

Recognition reviews show you a word or character and ask you to recall its reading or meaning. This is fast, works well on a phone, and is exactly what you need for reading menus, signs, and books. A reading-and-recognition game is a genuinely effective way to study, and it is the kind of practice you can do in short bursts anywhere.

Writing reviews ask you to produce the character by hand, stroke by stroke. This is slower, but tracing a kanji yourself builds muscle memory and helps you tell similar characters apart. It also deepens how well you recognize them later.

Here is the honest summary: recognition gets you reading sooner, and writing makes your memory of each character firmer. Many learners do mostly recognition for speed and add some handwriting for the characters that keep tripping them up. You can watch how a character is built in our animated stroke-order demo to see what writing practice looks like before you try it yourself.

How Kana Conbini can help

Kana Conbini is one friendly option among many, and it is free to start. If you want reading and writing in one place with the scheduling handled for you, here is what it offers.

• Smart reviews built in. Each word comes back right before you would forget it, with no scheduler to set up.
• The full range in one app. Over 10,000 real vocabulary words across the whole JLPT range, N5 to N1, all available now, each with native Japanese voice.
• Two ways to practice. A reading-and-recognition game called Conbini Run, plus a dedicated Write Kanji mode where you trace all 46 hiragana, 46 katakana, and over 2,000 kanji by hand in correct stroke order, with on-screen guides that fade as you improve.
• Free to start, no subscription. In the free tier, daily handwriting uses an energy meter that refills over time, and a one-time pack makes it unlimited if you want more.

If you are not sure where to begin, the learn hub has plain guides for each step, or you can start from the home page and try a few reviews today. Pick the app that you will actually open tomorrow, and let the timing do the rest.