# open-spaced-repetition/fsrs4anki

A modern Anki custom scheduling based on Free Spaced Repetition Scheduler algorithm

Repository: https://github.com/open-spaced-repetition/fsrs4anki
Canonical: https://ross.abutalabs.com/products/fsrs4anki
Homepage: https://github.com/open-spaced-repetition/fsrs4anki/wiki
Language: Jupyter Notebook
License: MIT
License Family: permissive
Topics: anki-addon, spaced-repetition-algorithm, anki, deep-learning, memory, spaced-repetition, srs, machine-learning, optimal-control, reinforcement-learning, fsrs, intelligent-tutoring-system
Last push: 2026-08-14T03:34:18+00:00

## Health v2 (maintenance only)
Score: 80/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 97, release rhythm 46, longevity 100
- inputs: {"age_days": 1455, "days_push": 19, "days_rel": 360, "gap_med": 23.0, "n_releases_24m": 9}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4053, forks 163 (observed 2026-08-28T04:08:33.912061+00:00)

## What it is
FSRS4Anki is a modern spaced-repetition scheduler for Anki based on the Free Spaced Repetition Scheduler (FSRS) algorithm. It replaces Anki's built-in scheduler and uses machine learning to optimize scheduling parameters from a user's review history.

## Use cases
- improve anki card scheduling accuracy
- personalize spaced repetition intervals with machine learning
- replace SM-2 scheduler with a better algorithm
- optimize review schedule from my anki review history
- remember more with fewer reviews in anki

## When to choose
- you use Anki and want more efficient, personalized review scheduling
- you want a data-driven scheduler that learns your memory patterns
- you are on Anki 23.10+ where FSRS is built in, or want the standalone add-on for older versions

## When to avoid
- you don't use Anki or another flashcard workflow
- you prefer Anki's default SM-2 scheduler and don't want to tune parameters
- you need a scheduler for a non-Anki spaced repetition app

## Facets
- artifact type: plugin
- maturity: active
- function: machine-learning, deep-learning
- domain: education, machine-learning
- platform: cross-platform
- tags: anki-addon, spaced-repetition, srs, fsrs, scheduler, memory-optimization, optimization, memory, desktop

## Member repositories
- open-spaced-repetition/fsrs4anki (main) score 80

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:33.912061+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:23:38.687902+00:00, confidence not recorded.
  - readme: https://github.com/open-spaced-repetition/fsrs4anki (fetched 2026-08-28T04:08:33.912061+00:00, sha 8717765051fe)
  - homepage: https://github.com/open-spaced-repetition/fsrs4anki/wiki (fetched 2026-08-29T09:15:54.021065+00:00, sha ead489b7d45d)
- Data as of 2026-08-30T08:39:29.467469+00:00.