FSRS
A next-generation spaced-repetition algorithm proposed in 2022 by open-source developer Jarrett Ye. It is grounded in memory psychology and introduces a three-parameter memory model encompassing stability, difficulty, and retrievability to predict optimal review intervals. The algorithm has been adopted by mainstream flashcard applications including Anki.
Timeline (last 90 days)
Anki has built in FSRS as an optional algorithm since version 23.10
FSRS (Free Spaced Repetition Scheduler) was developed by researcher Jarrett Ye using machine learning methods, modeling memory states with two variables: retrievability and stability.
FSRS (Free Spaced Repetition Scheduler) was proposed in 2022 by open-source community developer Jarrett Ye with the aim of replacing the SM-2 algorithm.
In FSRS, Stability describes the number of days required for memory retention to reach 90%, and Retrievability is the probability of successful recall at the current moment.
FSRS has been adopted by mainstream memory software such as Anki as an optional algorithm.
FSRS introduces a three-parameter memory model based on memory psychology, characterizing memory states along three dimensions: Stability, Difficulty, and Retrievability.
The agent uses an improved version of the FSRS algorithm, combining three dynamic signals—check-in time intervals, response speed when answering questions, and the user's familiarity with words—to calculate review nodes.
In 2023, Anki added FSRS (Free Spaced Repetition Scheduler) as an optional scheduler.
The FSRS algorithm, open-sourced in 2022 and based on the DSR model, has been shown to improve review efficiency by approximately 30% compared to SM-2.
All Facts (9)
Anki has built in FSRS as an optional algorithm since version 23.10
50%UnverifiedFSRS (Free Spaced Repetition Scheduler) was developed by researcher Jarrett Ye using machine learning methods, modeling memory states with two variables: retrievability and stability.
50%UnverifiedFSRS (Free Spaced Repetition Scheduler) was proposed in 2022 by open-source community developer Jarrett Ye with the aim of replacing the SM-2 algorithm.
50%UnverifiedIn FSRS, Stability describes the number of days required for memory retention to reach 90%, and Retrievability is the probability of successful recall at the current moment.
50%UnverifiedFSRS has been adopted by mainstream memory software such as Anki as an optional algorithm.
50%UnverifiedFSRS introduces a three-parameter memory model based on memory psychology, characterizing memory states along three dimensions: Stability, Difficulty, and Retrievability.
50%UnverifiedThe agent uses an improved version of the FSRS algorithm, combining three dynamic signals—check-in time intervals, response speed when answering questions, and the user's familiarity with words—to calculate review nodes.
50%UnverifiedThe FSRS algorithm, open-sourced in 2022 and based on the DSR model, has been shown to improve review efficiency by approximately 30% compared to SM-2.
50%UnverifiedIn 2023, Anki added FSRS (Free Spaced Repetition Scheduler) as an optional scheduler.
50%