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Scheduling

Last modified: 13/02/2026

Overview

Sprout uses FSRS (Free Spaced Repetition Scheduler).

FSRS chooses future review dates per card, based on your past answers and elapsed time.

How FSRS works

Each card tracks 3 values:

ValueMeaning
StabilityHow long memory lasts before dropping to target retention
DifficultyHow hard the card is for you (0–10)
RetrievabilityEstimated chance (0–1) you can recall it right now

When you rate a card, FSRS:

  1. Updates difficulty and stability.
  2. Calculates a next interval to meet your requested retention.
  3. Schedules the due date.

In practice, easy cards get longer intervals; forgotten cards get shorter intervals.

Card stages

StageDescription
NewNever reviewed
LearningEarly short-interval steps
ReviewMain long-interval stage
RelearningShort steps after a failed review

Presets

Choose a preset in Settings → Study → Scheduling or set values manually:

PresetLearning stepsRelearning stepsRetention
Relaxed20 min20 min0.88
Balanced10 min, 1 day10 min0.90
Aggressive5 min, 30 min, 1 day10 min0.92
Custom(user-defined)(user-defined)(user-defined)

Manual options

SettingDefaultDescription
Learning steps10, 1440Minutes between learning steps (comma-separated)
Relearning steps10Minutes between relearning steps
Requested retention0.90Target recall probability (0.80–0.97)

What the settings mean

  • Learning steps: short intervals for new cards before they move to Review.
  • Relearning steps: short intervals after an Again on a Review card.
  • Requested retention: target recall when card is due.

Higher retention increases workload (more frequent reviews). Lower retention reduces workload but increases forgetting.

TIP

0.90 is a strong default for most users.

FSRS console / log

You can inspect a card's FSRS history:

  1. Open the Card Browser.
  2. Select a card.
  3. Open card details to see ratings, stability, difficulty, and interval calculations.

Use this if a due date looks unexpected.

Reset options

ButtonEffect
Reset schedulingReset all cards to New (clears intervals, stability, difficulty)
Reset analyticsClear review history and heatmap data

Both options are in Settings → Reset and cannot be undone.

Released under the MIT License.