Charts

Last modified: 13/02/2026

Overview

Charts in Analytics help you understand workload, progress, and retention. Use filters first, then interpret chart changes.

Review Calendar Heatmap

Shows one year of daily review activity.

• darker day = more reviews
• hover for exact date and count

Use it to spot streaks and missed days.

Stage Distribution

Shows how cards are split across stages (New, Learning, Review, Relearning, Suspended). More cards in Review usually means the collection is maturing.

Future Due

Forecast of due cards over the next 30 days. Use it to spot upcoming heavy days before they happen.

Answer Buttons

30-day stacked view of grade choices (Again/Hard/Good/Easy). Frequent Again can signal unclear cards or too much difficulty.

New Cards Per Day

Shows how many new cards were added each day in the last 30 days. Useful for balancing input rate vs review load.

Stability Distribution

Histogram of stability values:

• low stability = short intervals
• high stability = longer intervals

Large low-stability clusters can indicate fragile recall.

Forgetting Curve

Compares your real retention with the FSRS expected curve. If real retention stays below expected, review Scheduling settings.

Filter behavior and empty states

• Time and scope filters affect every chart.
• Narrow filters can make charts look empty.
• Empty charts usually mean no matching data, not data loss.