What is FSRS?
FSRS stands for Free Spaced Repetition Scheduler. It uses review feedback and the time between reviews to update a model of a card’s memory state and calculate when to show it again. The aim is to space practice around what you are likely to remember.
FSRS is an open-source project, also available in Anki. Read the project introduction for its background.
What do Sooner and Later mean?
Try to recall the answer, then flip the card to check it. Give feedback about how well you knew the note:
| Your choice | What you mean | FSRS rating in Learnalist |
|---|---|---|
| Sooner | I don’t quite know this note. Show it again sooner. | Again |
| Later | I know this note. Show it again later. | Good |
Later is a signal that you knew the note. If you are simply too busy to review, leave it for another time rather than using Later as a snooze button.
You do not need four rating buttons to use FSRS. Anki’s FSRS FAQ also supports using Again and Good.
Why can two notes return at different times?
Each note has its own review history. One word may come easily; another may need repeated practice. FSRS updates its estimate using your feedback and when you reviewed, so the next interval can differ even when you choose Later for both notes.
The schedule is an estimate. Clear prompts, honest feedback, and returning to review still matter. Using FSRS alone does not establish that you have learned something or that one app produces better results than another.
How Learnalist implements FSRS
Learnalist uses FSRS-6 through the Go FSRS library. The server calculates the next review date. Sooner maps to Again and Later maps to Good, using shared default model parameters and a maximum review interval of 120 days.
FSRS scheduling applies to notes whose review history is ready for it. Notes without that prepared history retain the previous scheduling method while their reviews are recorded. This protects existing notes during the transition.
The account-free examples on this website demonstrate the controls. They do not save review history or run the scheduler.
Try it with your own material
Start with a word, sentence, question, or fact you want to remember. Try the web review controls, then make your first note.
If you are comparing tools, see Learnalist and Anki. The capture workflow, review controls, and way you organise your material matter alongside the scheduling algorithm.