Leech Detector

Introduction

This add-ons aims to offer new ways to understand how your card might not be leeches, based on more criteria than simply looking at lapses count

Features

Card Info VIew

Added new field to see the Leech status of a card and the key metrics allowing to determine if it's a leech or not.

<img src="https://github.com/JSchoreels/anki-addon-leechdetector/blob/main/images/card_info_view.png?raw=true" alt="Card Info View, New Leech Metrics" width="500" />

Browse View

• You can add to your queries new options to filters leeches :
  • leeches:all
  • leeches:active
  • leeches:recovering
  • leeches:recovered
  • leeches:healthy

Those flags combines as "OR", meaning the result will be all results merged.

You can also specify custom leech detection threshold, those are valid searches :

• leeches:active[drop_count=5,drop_ratio=.5]
• leeches:active[drop_count=5]
• leeches:active[drop_ratio=.5]
• leeches:recovered[drop_count=1,drop_ratio=.5] leeches:active[drop_count=5,drop_ratio=.5]

Note :

• All custom filters are under the hood replaced by *, and then only the search is filtered. So, (A leeches:active) OR (B leeches:recovered) will be equal to (A *) OR (B *) AND (leeches:active OR leeches:recovered. If you want proper evaluation of such queries, you should populate a card field with the leech status and filter on it like you would do with any normal card fields.
• If you specify more than once the same type of leeches filter, the last one will have priority. Example leeches:active[drop_count=1] leeches:active[drop_count=2] the drop_count=2 will replace the drop_count=1

Stats / Plugins Search

leeches:* filters are also supported in Stats screens and plugins doing card searches (for example Search Stats Extended).

• This compatibility patch is enabled by default.
• You can disable it in the addon config in Anki with "enable_stats_graphs_patch": false.
• Restart after this change.

Tools Summary Window

From Tools, you can open Leech Detector Summary to quickly see:

• Total leeches
• Active / Recovering / Recovered counts
• Per-deck split
• Double-click any deck table cell to open Browser directly on the corresponding search

<img src="https://github.com/JSchoreels/anki-addon-leechdetector/blob/main/images/tools_summary_view.jpg?raw=true" alt="Tools Summary Window, Leech Counts by Deck and Status" width="500" />

Contact

Issues / Feedback

• You can add the issues encountered or your feedback on this project : https://github.com/JSchoreels/anki-addon-leechdetector/issues
• If you don't have a github account, or want to discuss privately about some behaviours, you can contact me on Anki's Discord : @soundjona

Release Notes :

Unreleased

• Load Card Info lapse history in the background so it cannot block Anki's UI while another collection operation is running.

2026/03/04

• Support leeches:* in Stats / plugins searches
• Add fallback safety and config toggle (enable_stats_graphs_patch)
• Add leeches:healthy
• Add Tools > Leech Detector Summary window (with by-deck breakdown)

2025/04/29

• Add dynamic custom filters

2025/04/24

• Fix sorting in Browse view when doing leeches:* searches like leeches:recovered[drop_count=1,drop_ratio=.5] leeches:active[drop_count=5,drop_ratio=.5]