Spaced Repetition for Japanese: A Beginner's Guide

If you've spent any time in Japanese learning communities, you've seen the letters SRS: spaced repetition. It's the engine behind WaniKani, Anki, Bunpro, and Cotobara. This guide explains what it is, why it's so well suited to Japanese, which app to run it in, and how to use it without drowning.

What spaced repetition actually is

Your brain forgets on a predictable curve, the forgetting curve. A word you learn today is mostly gone in a few days unless you revisit it. But each time you successfully recall it, the memory gets more durable and the next "safe" gap before you forget gets longer.

Spaced repetition automates that. It shows you a word right before you're about to forget it, then stretches the interval each time you get it right: 1 day, then 3, then a week, then a month, then months. Words you struggle with come back often; words you know get out of your way.

The result: you spend your review time almost entirely on the things you're about to lose, instead of re-drilling words you already know.

Why it fits Japanese so well

Japanese is unusually vocabulary- and character-heavy. To read comfortably you need thousands of words and a couple thousand kanji, far too many to hold with brute-force cramming. SRS is the difference between:

• Cramming: memorize a list for a test, then watch most of it evaporate over the following weeks.
• SRS: learn a few words a day, and keep almost all of them for as long as you keep reviewing.

Over months, that compounding retention is what separates people who keep making progress from people who restart every year.

The spaced repetition apps for Japanese

Every tool below runs the same underlying idea. What differs is what it schedules, and whether you have to supply the material yourself.

Anki

The general-purpose one. It schedules whatever you give it, which makes it the most capable and the most work: you source or build the deck and decide the settings. FSRS is built in now and schedules well on its defaults, so the scheduling is no longer the part you have to research. (Which deck?)

Cotobara

A vocabulary SRS with the material already curated, JLPT- and frequency-ordered, and the scheduling already tuned. Ours, so weigh it accordingly. Covered properly at the end of this post.

WaniKani

Schedules kanji characters and readings, not general vocabulary. Its intervals are fixed and deliberately unhurryable. Excellent at that one job. (Is it enough for the JLPT?)

Bunpro

The same engine pointed at grammar points instead of words, tracked by JLPT level. It reviews grammar you are learning elsewhere rather than teaching it from scratch.

jpdb

Builds a frequency-ordered deck from a specific anime, novel or game so you can pre-learn its vocabulary before you start. Free, dense, and assumes you already know what you want to read.

renshuu

Covers vocabulary, kanji and grammar in one scheduler with a generous free tier. Broad, and correspondingly more to configure.

Most working setups are two of these: one for vocabulary and one for either kanji or grammar. Running three SRS apps at once is the most common way people end up with a review pile they abandon.

The catch: recognition vs recall

A big warning. Many SRS setups quietly train only recognition: you see the word and confirm you know it. But real Japanese demands recall: producing the word when you need it. If your cards let you pass by recognizing, you'll build a false sense of progress. We break this down in recognition vs recall. Good SRS makes you retrieve, not just recognize.

How to use SRS without burning out

1. Keep the daily new-word count modest. Every new word costs roughly a dozen reviews over the following months. For most people 5–10 a day is the honest ceiling; the learners who set it much higher tend to drown in the review pile and quit.
2. Do reviews every day, briefly. Consistency beats marathon sessions; the schedule assumes you show up daily.
3. Don't skip the backlog dread. If reviews pile up, do a capped number and let the rest wait. Never binge-clear then quit.
4. Learn words in context. A word attached to a real sentence, audio, and an image sticks far better than an isolated pair.
5. Trust the algorithm. Don't manually re-drill words it hasn't scheduled; that's the whole point of letting it decide.

Which SRS should you use?

• You want to build and own your system: Anki. Free, endlessly configurable, and you accept the setup and maintenance as the price.
• You want to start reviewing today: a curated vocabulary SRS, so the deck and the settings are not decisions you have to make first.
• You need kanji specifically: WaniKani alongside a vocabulary tool, not instead of one.
• You need grammar: Bunpro alongside whatever you are learning grammar from.
• You are reading one specific thing: jpdb, to front-load its vocabulary.

If you are choosing between Anki and a curated system, the side-by-side comparison goes into where each one actually wins.

Where Cotobara fits

Cotobara is a spaced-repetition system built specifically for Japanese vocabulary, with the two things generic SRS often lacks: a recall-focused review engine, and real context, natural-sounding audio and example sentences on every word, so each rep is doing more work. It also handles the "what should I even study" problem with a curated, JLPT-aligned corpus, so you're not building decks. On ordering, see the best order to learn Japanese vocabulary.

Spaced repetition won't learn the words for you, but it's the best answer anyone has found to the forgetting curve. Use it on recall, in context, every day, and the words stay learned.