Pack Optimizer

Pro

The Pack Optimizer makes your resource pack smaller without changing how it looks — faster to download for players, lighter on your server’s bandwidth.

What it does

Lossless PNG recompression — every texture is re-encoded at maximum compression. Pixels are identical; only wasted bytes go. Always on.
Metadata stripping — editor comments, timestamps and other ancillary chunks are removed.
Optional downscaling — if some textures are larger than they need to be (a 512×512 that renders as 16×16), you can cap them to a maximum size. This is lossy, so it’s off by default and opt-in per run.

Upload the pack, pick whether to downscale, and you get back the optimized .zip plus a summary of how much you saved.

Downscaling reduces image resolution and cannot be undone — keep your original. Only use it when you know your textures are oversized. The lossless recompression is always safe.

When to use it

Before publishing a pack, to cut the download size — especially useful for packs with lots of textures (see Server Sync, where a smaller pack deploys faster).
After a merge, which can bundle textures exported at full editor quality.
Any time your pack is heavier than it should be.

Pair it with the Validator to confirm nothing broke, and see Free vs Pro for what Pro unlocks.