Polymer PackSquash
by tomalbrc
Polymer PackSquash runs the PackSquash optimizer on resource packs that Polymer generates, so servers ship smaller packs without a manual compression step.
What it does
PackSquash is a resource pack optimizer, and this mod wires it into Polymer's pack generation. After Polymer finishes building a resource pack, the mod runs PackSquash on the result and, when the run completes successfully, serves the optimized version to players instead of the raw output. Changes to the pack are picked up on the next run without any manual compression.
The mod fetches the latest PackSquash release on first use and creates a packsquash.toml file in the Polymer folder. Server owners can point the mod at a different PackSquash binary or TOML configuration file, turn the integration on or off, print the PackSquash output log, and write a log file recording hash changes for debugging. When the pack is unchanged, PackSquash is bypassed rather than run again.
Polymer PackSquash is a server-side only mod, so players join without installing anything. It requires Polymer, and it is published for Fabric only, with files for 26.1.2 as the latest build, dated 2026-03-29. The mod is released under the GNU Lesser General Public License v3.0 only and is open source.
Key features
Automatic pack optimization
Each Polymer resource pack is passed through PackSquash after it is generated, so compression runs with every change.
Skipped unchanged runs
When the pack has not been altered since the previous run, PackSquash is bypassed, which keeps repeated server starts quick.
Configurable paths
Options set the PackSquash binary path and the TOML configuration file path, so a custom install can be used.
Output and hash logging
The PackSquash output log can be printed, and a log file records hash changes for troubleshooting.
Compatibility
Latest build for each game version and loader.
26.x3 of 3 versions with builds
1.21.x6 of 6 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Who it’s for: Server owners who distribute Polymer resource packs and want them compressed automatically rather than by hand.
How it compares
Polymer - Quality of Life is a client and server Fabric mod under the MIT License, published for 1.21.5 – 26.3, so it is installed on both sides and does not touch pack compression. Better Server Packs (Fabric) is server-side only under the MIT License, covering 1.21 – 26.3, and handles server pack delivery rather than optimization. Runtime Hash Updater is also server-side only, under the CC0 1.0 Universal license, covering 1.19 – 26.3, and updates pack hashes at runtime.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Polymer PackSquash | Fabric | 1.21.6 – 26.1.2 | Server-side only | 2026-03-29 |
| Polymer - Quality of Life | Fabric | 1.21.5 – 26.3 | Client and server | 2026-09-28 |
| Better Server Packs (Fabric) | Fabric | 1.21 – 26.3 | Server-side only | 2026-09-21 |
| Runtime Hash Updater | Fabric | 1.19 – 26.3 | Server-side only | 2026-09-15 |
Questions
Does Polymer PackSquash need Polymer installed?
Does the mod have to be installed on the client?
Can a custom PackSquash binary be used?
In the catalog
Polymer PackSquash is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 15,189 mods support Minecraft 26.1.2.
More from tomalbrc
Similar mods
What the author says
This mod integrates PackSquash with Polymer’s resource pack generation to automatically optimize generated resource packs so you don't have to manually compress after changes. These are the default paths the mod will use. You can adjust them in the configuration file config/polymer-squasher.json
Official listing
- Modrinth page
- modrinth.com/mod/polymer-squasher
- Owner
- tomalbrc
- Published
- 2025-08-11
- Updated on Modrinth
- 2026-03-29
- Facts verified
- 2026-10-15