Async Pack Scan Mod (1.21.7, 1.20.4) – Fix Lag from Resource Pack Scanning

Async Pack Scan Mod (1.21.7, 1.20.4) is a performance-enhancing utility mod that eliminates lag spikes caused by Minecraft’s default synchronous resource pack scanning. In vanilla and many modded environments, opening or resizing the resource pack menu can lead to noticeable stutters, especially when multiple large packs are installed. This mod solves that issue by offloading the scanning process to a separate thread.

By improving how resource packs are handled in the background, Async Pack Scan ensures smoother interactions with the pack selection screen and boosts overall responsiveness, particularly for users who frequently switch packs or use mods that extend scan times.

Key Features:

Asynchronous Pack Scanning
Moves the resource pack detection process to a background thread, preventing the game from freezing or lagging during pack updates or UI interaction.
Reduces Lag When Resizing or Updating UI
Prevents stutters caused by synchronous scanning when the resource pack organizer screen is opened, closed, or resized.
Better Performance with Multiple Packs
Especially helpful for users with large or complex resource packs, where load times can be significant.
Compatible with Mods That Extend Scan Time
Works well with mods like Respackopts, which can increase the duration of pack scans. Async Pack Scan helps keep performance stable even in such cases.

Screenshots:

Why Use Async Pack Scan?

If you notice FPS drops or input lag when adjusting resource packs, Async Pack Scan Mod offers a simple and lightweight fix. It doesn’t add new features or modify resource packs themselves it just makes your game run smoother when working with them.

Perfect for: