Spaced Repetition

SM-2 schedules flashcard reviews using an 'easiness factor' (EF). Grades of Hard or better stretch the interval (1 day, 6 days, then interval × EF); an 'Again' resets the card to a 1-day interval and lowers its EF.

Again means you forgot (counts as quality 0), Hard means you barely remembered (quality 3), Good is a normal recall (quality 4), and Easy is instant recall (quality 5). Higher grades grow the next interval faster.

New cards come back in 1 day, then 6 days if you remember them. After that the gap multiplies by the card's easiness factor, so well-known cards return in weeks or months.

Press Again. The card's interval resets to 1 day, its repetitions restart, and its easiness factor drops — so it comes back sooner until you know it.

Yes, in your browser's localStorage. Decks, cards, and review schedules persist between visits on this device, and nothing is sent to a server.