— A study platform for the hardest exams of your life

Highlighting feels productive. It isn't.

Onion is a study platform built around active recall, spaced retrieval, and retrieval under stress — the methods that actually work, made effortless to do every day.

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On the name

Knowledge has layers. So does the work of mastering it.

01 · The problem

You don't have a study problem. You have a feedback problem.

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Cramming feels effective.

Re-reading and highlighting raise familiarity, not retrieval. Familiarity collapses on test day. You walk out wondering what happened.

02

The illusion of mastery is engineered.

When the textbook is open, every fact looks like one you knew. When it's closed, half are gone. You won't notice the gap until the gap is the test.

03

Decision fatigue eats your willpower.

Choosing what to study is studying. By the time you start, you've already burned the focus you needed to do the work.

02 · The philosophy

Seven pillars. No shortcuts.

Onion is built around seven practices that have a half-century of evidence behind them. We don't make them more comfortable — we make them harder to skip.

01Onion ReadingThree structured passes — overview, concepts, nuances. Highlighting is disabled, because highlighting is the lie.
02Active recallEvery chunk is followed by a closed-book question. The page is blank until you've earned what's on it.
03Spaced retrievalFSRS scheduling decides when you see things again. Not when you feel like reviewing them.
04Retrieval under stressPractice with a timer running, sometimes. The exam will.
05Confidence calibrationYou rate confidence, then we score you. The gap is the lesson.
06The error notebookEvery miss is recorded, clustered, and resurfaced until you stop missing it.
07Pareto leverageWe flag the 20% of material that produces 80% of the points. You spend your hours there.

03 · How it works

One PDF in. Three passes through. Mastery out.

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Drop in your material.

Upload a PDF, paste a syllabus, or import a textbook. Onion parses, chunks, and indexes it — embeddings for retrieval, structure for layered reading.

Peel through the layers.

Three reading passes — overview, concepts, nuances. Each one ends with closed-book recall, scored against a rubric you set.

Show up, every day.

FSRS schedules tomorrow's review automatically. Your error notebook surfaces the clusters you keep missing. You show up. It does the rest.

The exam doesn't wait. Neither should your prep.

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