About needspace

Remember more. Cram less.

needspace is a flashcard app that decides when you should see a card again, not you. Write what you're trying to learn once, rate how well you remembered it each time you review, and the app quietly rebuilds your study queue around your own memory.

How spaced repetition works

Every card follows a forgetting curve: retention drops steadily until you review it again, which resets the curve and stretches the gap before the next review. That growing gap is the whole point - reviewing a card you already know wastes time, and reviewing one you've forgotten wastes the review. The trick is catching each card right as it's about to slip.

needspace times that moment using FSRS, an open scheduling algorithm built from real review data rather than a fixed formula. Every time you rate a card Again, Hard, Good, or Easy, it updates its estimate of that card's difficulty and how quickly you tend to forget it, then picks the next review date accordingly. Cards you find easy drift weeks or months apart; cards you keep missing come back the next day.

What you can do here

Build collections. Write cards by hand, front and back, with optional images on either side.
Import a CSV. Already have a word list or a deck exported from somewhere else? Bring it in as a two-column front,back file.
Study in short sessions. Only cards that are actually due show up - no scrolling through ones you already know.
Track your progress. Review history, streaks, and success rate live on your analytics page, and milestones unlock achievements as you go.
Share a public profile. Show off your streak and achievements, or keep everything private - it's your call.