Modscraper Modscraper Minecraft

Sort By

Type

Content

Tags

Async Pack Scan logo

Async Pack Scan

Mod

by JFronny

Fixes lag while changing resource packs

Type

Mod

CurseForge Downloads

48,666

CurseForge ID

881560

Modrinth Downloads

1,513,269

Modrinth ID

FuRR0tKd

Last Updated

Oct 28, 2026

Description

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.

Suggestions and Support

Compatibility

Mod Loaders

Fabric

Game Versions

1.20 1.20.2 1.20.4 1.20.5 1.21 1.21.1 1.21.2 1.21.3 1.21.4 1.21.5 +9 more

Recommended Gear

Affiliate

Hardware and extras that pair well with this mod.

Minecraft Enderman Character Plush

Minecraft Enderman Character Plush

Enderman plush toys, and a reliable gift for a younger player.

View on Amazon →

As an Amazon Associate I earn from qualifying purchases.

Similar Mods

Luminax

Luminax

Adds a bunch of simple glowing blocks to the game

Mod 15,609,348 143.5K this week
BisectHosting Server Integration Menu

BisectHosting Server Integration Menu

BisectHosting Server Ordering Menu

Mod 15,582,467
Exotic Birds

Exotic Birds

This mod adds a variety of different birds into your game.

Mod 15,577,814 14K this week
NoMoWanderer

NoMoWanderer

Adds various things to the game to help make the Wandering Trader less annoying.

Mod 15,573,922 10.5K this week
Friendly Fire

Friendly Fire

Modifies combat to prevent friendly fire to pets and other mobs.

Mod 15,571,396
Enchanting Plus

Enchanting Plus

Enchanting Plus

Mod 15,542,691 11K this week

Included in Modpacks (32)

Show fewer
Cobblemon Islands Server Modpack Cobblemon Islands Server Modpack Cobblemon - Poke Legends Cobblemon - Poke Legends Gobba's Crystal PVP Modpack Gobba's Crystal PVP Modpack Crystal Verse Crystal Verse Plutonium Plutonium Simple Performance Simple Performance Ranked Optimized Ranked Optimized Diamond Age Diamond Age duziy's PvP Optimized duziy's PvP Optimized SBooster Official SBooster Official BottomlessThought's Realism BottomlessThought's Realism OptiCool OptiCool Celestial Performance [QoL] Celestial Performance [QoL] Negative Fps Negative Fps Optimization Q Optimization Q Sodtesium Sodtesium ORICHILL Client ORICHILL Client Outerworlds Outerworlds Slemprix's Essentials Slemprix's Essentials Eshkere-modpack Eshkere-modpack VortexCraft VortexCraft Ideal Vanilla Ideal Vanilla Properly Optimized // [1.3.2] Properly Optimized // [1.3.2] Fedorista's Modpack Fedorista's Modpack BananaMC BananaMC Just a Random Vanilla Adventure Just a Random Vanilla Adventure MacOS Ready MacOS Ready Just Vanilla+ Just Vanilla+ Mac Native Mac Native Smolder's Ultimatum Smolder's Ultimatum CRINGELAND - a Vanilla+ CRINGELAND - a Vanilla+ VanillaBoostP VanillaBoostP

External Resources

CurseForge Modrinth Source Code Issues