K2 vs WaniKani
A WaniKani alternative that sets its pace by you.
WaniKani walks everyone through the same levels, unlocking new kanji on a schedule. K2 watches how you answer and adds new kanji when the current ones have cooled. See how the two compare, and which one fits the way you study.
No account needed · 1,006 kyōiku kanji, grades 1–6 · Progress saves in your browser
K2 and WaniKani, side by side.
Both teach kanji with spaced repetition. They disagree about who sets the pace.
| Topic | WaniKani | K2 |
|---|---|---|
| What you learn | Over 2,000 kanji and over 6,000 vocabulary words, in WaniKani’s own order, built up from radicals. | 1,006 kyōiku (school-grade) kanji, grades 1–6, in grade order, plus the compound words built from them. |
| How it teaches | A lesson for every radical, kanji and vocabulary word, each with a mnemonic. | Recall drills, with no lessons or mnemonics. Each card shows its readings and meaning as you go. |
| What it asks you | Radicals ask for a name. Kanji and vocabulary ask for meaning and reading, separately. | Separate modes for meaning, reading, writing (see the meaning, recall the kanji) and listening, each tracked on its own. |
| When reviews come up | Items move through fixed stages, Apprentice, Guru, Master, Enlightened and Burned, with intervals from hours to months. | No stages and no intervals. Every card is drawn at random, weighted toward the kanji you miss, so those come back within moments. |
| After a wrong answer | The item drops one or more stages, and its next review comes sooner. | It becomes twice as likely to come up, so you see it again sooner. |
| When new kanji arrive | Kanji unlock once their radicals reach Guru. The next level unlocks when 90% of the current level’s kanji reach Guru. | Once you mostly know the kanji you are learning (average p < 0.15), K2 adds 5–10 more. There are no levels to clear. |
| Vocabulary | A word unlocks when its kanji reach Guru. | A compound word unlocks once you have nearly mastered every kanji in it (p < 0.1 for each). |
| Beyond kanji | Japanese kanji and vocabulary. | Japanese grammar drills (particles, counters, te-form, keigo), and the same engine for Chinese, Korean, Spanish, French, Latin and more. |
| Cost | See WaniKani’s site. | Free, in the browser, with no account needed. |
A set curriculum, or an adaptive one.
Three differences decide which one suits you. The K2 algorithm page explains why K2’s approach works.
A pool, not a path
WaniKani’s kanji come in a set order, and each level opens when 90% of the last one’s kanji reach Guru. K2 has no levels: once your kanji have mostly cooled (average p < 0.15), it brings in 5–10 more. Struggle, and nothing new arrives until you have steadied.
avg p < 0.15 → +5–10 newDrills, not lessons
WaniKani teaches: every radical, kanji and word has a lesson and a mnemonic. K2 drills: cards show readings and meaning as you go, and the engine’s job is to put the right card in front of you at the right moment.
right → p ÷ 2 · miss → p × 2Start where you are
K2’s kanji follow the school grades, so if you know the early grades you can say so and start further in; any you then miss heat back up. Compound words unlock once you have nearly mastered every kanji in them (p < 0.1 each).
compound unlocks: every kanji p < 0.1Which one fits you.
An honest answer depends on how you like to learn.
Choose WaniKani if…
- You want a guided course, with a lesson and a mnemonic for every item.
- You want to go past the grade-school kanji toward the larger set WaniKani covers.
- You like learning kanji through their radicals.
- You value a steady, predictable pace that is the same for everyone on the same level.
Choose K2 if…
- You want to start on kanji immediately, for free, without an account.
- You want the pace set by how you are actually doing, not by fixed intervals.
- You already know some kanji and want to skip ahead.
- You want grammar drills, or another language, on the same engine.
Sources
Claims about other products were checked against their own public pages in October 2026. Features change; follow the links for the current picture.