What your stats tab is actually telling you

A few months ago a user wrote to us with a complaint we ended up framing: "I've been using the app for six weeks and I have no idea if I'm actually learning anything." Fair. She was doing her reviews every day, but nothing in her daily routine told her whether all those taps were adding up to real Chinese.

They were — she just didn't know where to look. So this post is the tour we gave her: every number in the stats tab, what it actually measures, and which ones are worth your attention.

The streak

The flame icon counts consecutive days with at least one completed review session. That's the whole rule. Five minutes on the bus counts exactly the same as an hour at your desk.

We made it that forgiving on purpose. The hard part of learning Chinese isn't any single study session, it's still being there in month four. A streak you can keep alive with five minutes is a streak you'll actually keep — and five minutes a day is genuinely enough for the algorithm to work with. Do the math and it comes out to roughly a thousand words a year.

One thing people always ask: if you break your streak, your words are fine. Nothing gets deleted, no progress is lost, your reviews just wait for you. The counter resets, your Chinese doesn't.

Words known

This is the number we'd tell you to care about most. It's not "words you've seen" — it's words you've answered correctly enough times, spread out over enough days, that the SM-18 algorithm considers them stable in your long-term memory.

That strictness is what makes it useful. When Words known says 412, you can trust it. It will grow slower than you'd like — a word usually needs several successful reviews over a few weeks to graduate — but it never lies to you, and watching it climb is watching your actual vocabulary grow.

Reviews per day

A simple bar chart of how many cards you reviewed each day. It's less about pride and more about workload: if you add three new decks at once, you'll see the bars spike a couple of weeks later when all those new words come due. If your daily pile starts feeling like a chore, this chart tells you why — and the fix is usually to slow down on new words for a while and let the backlog drain.

Accuracy

The percentage of reviews you get right, overall and per deck. Don't chase 100% — if you never miss, you're reviewing things you already know too well, and the algorithm will stretch your intervals anyway. Somewhere in the 80s is the sweet spot: hard enough that you're learning, easy enough that you're winning.

Where accuracy earns its place is per deck. When your food deck sits at 92% and your business deck at 68%, you know exactly where your next study session should go.

HSK coverage

This one maps every word you know against the official HSK lists, level by level, HSK 1 through HSK 9. It's the chart users mention most in emails, and we get why: "I know 78% of HSK 3" is a sentence you can plan around. It tells you whether you're ready to register for the exam, which level to actually book, and which gaps to close before test day.

Even if you never plan to sit the HSK, it's the closest thing to an honest answer to "how good is my Chinese, really?"

Milestones

Your first 100 characters, a finished deck, a 30-day streak — the app pops a small celebration when you cross these. We added them because these moments are weirdly easy to miss. Nobody notices the day their vocabulary quietly passes 500 words. The app notices.

If it's been a while since you looked, open the stats tab tonight. Six weeks in, our user from the first paragraph had 300 words the algorithm considered solid — she just found out about it three weeks late. Don't be her. 📈