Skip to content

Async Pack Scan

Speeds up the resource pack organizer screen

Fabric
Loaders
Fabric
Downloads on Modrinth
1.6M
Followers on Modrinth
134
versions
20
Updated
September 16, 2026Sep 16
Published
in 2023

At a glance

Runs on Fabric
For Minecraft 1.20.4–1.20.5, 1.21–26.3 …
Client only — no need to install it on the server
Latest version — 26.3.0 from September 16, 2026
Requires LibJF
License MIT — free
Where it's needed
In gamerequiredOn servernot needed

Install in the game only; not needed on the server

Game versions1.20.2, 1.20.4–1.20.5, 1.21–26.3 …

Note

This mod no longer seems to be required as of MC 1.20.5. Nonetheless, interactions between mods might still cause an issue, so I will keep updating it for the time being. If you experience no lag spikes, you can safely remove this mod.

Original Description

In vanilla minecraft, the list of resource packs is refreshed by scanning all possible sources synchronously.

Generally, this is not a problem, but in the resource pack organizer screen, this scan is performed whenever it is resized and every twenty ticks.

If another mod (such as Respackopts) hooks into the pack scan and increases its duration even slightly, this leads to major lag spikes and makes the screen near-unusable when using more than a few packs.

This mod fixes that issue by moving this computation to another thread and scheduling a scan task on those events instead, drastically improving perceived performance.

Since the vanilla code is designed for synchronous execution, this can cause issues like crashes in edge cases, but worked well enough in my testing.

FAQ

How to install Async Pack Scan?

Install Fabric for your Minecraft version, download Async Pack Scan for the same version and loader, put the file into the mods folder and launch the game with the loader profile.

Which Minecraft versions does Async Pack Scan support?

Async Pack Scan has builds for Minecraft 1.20, 1.20.2, 1.20.4–1.20.5, 1.21–26.3.

Is Async Pack Scan needed on the server?

Client only — no need to install it on the server

License and source
MIT Licensefree to use and share with credit to the author
Original — Modrinth↗Files unchanged, verified with SHA-512Is this your mod? For rights holders

The site uses cookies: the necessary ones for sign-in and the theme, plus the Yandex Metrica and LiveInternet visit counters — they show us how the site is used. We have no advertising cookies. More