Anki freezes and experiences excessive memory consumption when creating custom study sessions by tag or card state on macOS

Anki Help
1

I am experiencing a reproducible issue when attempting to create a custom study session using tags or card states.

When selecting either option, Anki becomes unresponsive and its memory consumption begins increasing continuously. Memory usage can exceed 20-30 GB, making the application unusable.

The issue persists in safe mode without addons. The issue does not take place on the windows desktop client using the same deck (anking deck which has several thousand cards.

Environment

  • Operating system: macOS 27.0.1

  • Hardware: 13-inch MacBook Pro (M1, Apple Silicon) 16 GB of RAM

  • Anki version: Version ⁨26.09.4 (c06370ff)⁩
    Python 3.13.17 Qt 6.11.2 Chromium 140

Steps to Reproduce

  1. Launch Anki.

  2. Navigate to the custom study session creation interface.

  3. Attempt to create a custom study session using the tag selection option.

  4. Observe application responsiveness and memory consumption.

Expected Behavior

Anki should open a window where included and excluded tags are selectable. Memory usage should not increase to the observed degree.

Actual Behavior

  • Anki becomes unresponsive during the creation process.

  • Memory consumption continuously increases.

  • Memory usage can exceed 20-30 GB (12GB memory + 16 GB of swap).

  • The application remains frozen until force-quit.

Troubleshooting Already Performed

The issue persists under the following conditions:

  1. Safe Mode: Reproduces with all add-ons disabled.

  2. Software rendering: Switching to software rendering does not resolve the issue.

  3. OpenGL rendering: Switching to OpenGL rendering does not resolve the issue.