Chinese flashcards with FSRS

Wanyu is a Chinese flashcard app with real FSRS —the open spaced-repetition algorithm— and nothing to set up. Every day it puts in front of you exactly the words you’re about to forget, and all you do is grade them with a tap.

What is spaced repetition inside Wanyu?

Reviewing a word just before you forget it is what locks in the memory with the least effort. The hard part has always been working out that moment for each word and each person. That’s what FSRS does: it keeps a small model of your memory per card and schedules the next review for when your chance of recalling it starts to drop.

This isn’t a clone or a formula “inspired by” something: Wanyu uses the open ts-fsrs library, the same FSRS implementation, running on your device with no cloud. And there’s nothing to turn on and no parameters to touch —it ships by default. If you want the algorithm itself, where it comes from and how it differs from the classic method, we cover that separately in what is FSRS.

What does a review look like, step by step?

The Study screen opens with a “For today”: the reviews FSRS scheduled for today plus whatever new words fit. You see the card, try to recall it, flip it, and grade it with one of four options:

• Again — you missed it; it comes back soon.
• Hard — you got it, but it took work.
• Good — you recalled it fine.
• Easy — no hesitation; space them out further.

Each grade updates that card’s model and decides when it returns. The session doesn’t land all at once: it’s served in short batches —the small window that actually fits your day— dragging forward what you missed so nothing slips through. You grade; the algorithm does the rest.

Which cards does it work with?

All of them. FSRS moves the words from the HSK library and the decks you build through the exact same engine: paste song lyrics, an article or your show’s subtitles into the reader or into Import, and whatever you capture goes into the same review system. One engine for what you study from the library and for what you bring in from your own life.

What numbers does it show you?

The algorithm’s, not a game’s: real retention —how much you actually remember— and words mastered. No streaks, no lives, no “streak shaming” that punishes you for skipping a day. The metrics are there so you can see honest progress, not to hook you.

Does it work offline?

Yes, completely. FSRS is a formula that runs on your phone: no internet, no account, no servers. Your data lives on your device and leaves with you whenever you want. And the review engine is free forever, including with your own imported decks —more on the no-subscription page.

What it does NOT do (the honest part)

• No cloud sync. There are no accounts and no servers, so moving your progress to another device means exporting and importing a JSON file by hand. In exchange, nothing of yours leaves your phone unless you decide it does.
• No Anki (.apkg) import. There’s no review-history migration and no Anki file reader. What you can do: paste any list or text and Wanyu turns it into a deck with dictionary glosses, flagging the doubtful ones in amber.
• Consistency is on you. FSRS optimizes when to review; it doesn’t study for you. If you don’t open the app nearly every day, no algorithm will save you.

If you’re coming from Anki and wondering what really changes, we put them side by side in Wanyu vs Anki: the algorithm is the same one; what changes is everything around it.

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