FLASHSIDE

Spaced repetition app

A spaced repetition app that schedules every review with FSRS

A spaced repetition app shows you each card again just before you would forget it. Flashside does this with FSRS: you grade a card again, hard, good or easy, and it picks the next review date from that card’s stability and difficulty. It is free on iPhone, Android and the web, and there are no intervals to configure.

How it schedules

From one tap to the next review date

  1. 01

    You answer, then grade

    Recall the answer before you turn the card, then tap again, hard, good or easy. That grade is the only input the scheduler needs.

  2. 02

    FSRS updates the card

    Each card carries a stability, in days, and a difficulty from 1 to 10. Your grade moves both, from the card’s own history.

  3. 03

    The next date is computed

    The review lands on the day your chance of remembering falls to your target retention. Before you grade, each button shows the interval it would give.

  4. 04

    Today’s queue is only what is due

    Cards you still know stay out of the way. When the queue is empty, you are done for the day.

How it is implemented, weight by weight →

The study plan

Minutes a day in, a daily load out

Spaced repetition decides when a card comes back; the study plan decides how much new material you take on. Tell it how many minutes a day you have and, if there is one, the exam date. It sets the new-card rate, shows today’s minutes, and says plainly whether the date is within reach. It is free for everyone.

Let the scheduler take the first ten cards

Write them tonight, grade them, and the first reviews are already on the calendar.

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Questions

Questions about spaced repetition

What is a spaced repetition app?+

An app that shows each card again just before you would forget it. It records how well you answered and moves the next review further out for cards you know and closer for cards you missed, so your time goes to what is slipping.

Which algorithm does this spaced repetition app use?+

Flashside schedules with FSRS 6. It models every card with a stability, a difficulty and the probability that you still remember it, and sets the next review for the day that probability falls to your target retention.

How it is implemented, weight by weight →

Is there a free spaced repetition app?+

Flashside is free to learn on iPhone, Android and the web: writing, studying, scheduling, syncing, importing and the study plan cost nothing, with no advertising. Flashside Plus is an optional subscription for extras; flashside.app/plus lists them and the prices.

What Flashside Plus adds and costs →

Do I have to configure intervals?+

No. You grade each card again, hard, good or easy, and the scheduler does the rest. If you want, you can set a target retention: higher means shorter intervals and more reviews.

How many new cards a day should I study?+

As many as fit the minutes you really have. Flashside’s study plan takes your minutes a day and, if there is one, an exam date, then sets how many new cards you take on and tells you whether the date is within reach.