Guide · Study science
Spaced repetition is a study schedule that shows you each fact just before you would have forgotten it. It is built on one of the oldest findings in memory research — the forgetting curve — and a good app handles all the timing for you.
In the 1880s, Hermann Ebbinghaus measured how quickly we lose newly learned information. The result, now called the forgetting curve, is steep: without review, memory of fresh material drops sharply within hours and days. The fix is not to study harder on day one — it is to revisit the material at spaced intervals, each review flattening the curve a little more.
After answering, you tap how it went — Again, Hard, Good, or Easy. That single judgement is all the algorithm needs.
The SM-2 algorithm grows the interval for cards you know and collapses it for cards you miss, tracking an "ease" value per card so timing adapts to you.
Each day the app surfaces exactly the cards due — no more, no less — so a session stays short and finishable.
You should never be calculating intervals by hand. Brainfy runs an SM-2-style scheduler under the hood: you just answer honestly and review what is due. If you want the deeper feature tour, see our spaced repetition app page.
Ordinary reviewing treats every fact the same. Spaced repetition reviews each fact on its own schedule, timed to the moment you are about to forget it, so effort goes where it counts.
SM-2 is a well-known scheduling formula that uses your rating of each card to decide the next review date, stretching intervals for easy cards and shrinking them for hard ones. Brainfy uses an SM-2-style scheduler.
Daily is ideal because the schedule assumes you clear due cards each day. Even 10 to 20 minutes keeps the queue from piling up.
Yes — anything you can phrase as a question and answer benefits, from vocabulary and definitions to formulas and concepts.
You will have a larger due pile, but nothing is lost. A good scheduler caps new cards and lets you chip through the backlog without penalty.
Brainfy is built by Aihan Mifthas · Last updated 2026-05-31. Open Brainfy →