StackUp! is a Minecraft mod which lets you remove the vanilla item stack size limit of 64, instead setting it as high as you want*.
You can find an introductory tutorial (assuming 1.12) here.
Usage of the mod is as follows:
For 1.13+ users
- StackUp! operates in the form of an expansion to the datapack format. Use the built-in scripting system in datapacks to modify stack sizes.
- The changes will synchronize from server to client!
For 1.12 users
- Upon installation, a "stackup.cfg" configuration file will be created. Do not forget to open it and set the maxStackSize configuration option - otherwise, items will still be hard-limited by 64! The config option sets the maximum global stack size. You can set it to anything you want - 99? Five hundred? Ten thousand? One million? The sky is the limit!
- After this, you may notice that all of the blocks and items still have a stack size of 64! That is correct - to prevent balance-breaking issues, StackUp! will only change default stack sizes by itself in very rare cases. To change items' stack sizes, you can either use the built-in scripting system introduced in StackUp! 0.2.0, or an external mod such as CraftTweaker.
This patch has been tested with a lot of mods (including, but not limited to Refined Storage, Applied Energistics 2, Charset, Iron Chests, Quark and Rustic), but compatibility is not 100% guaranteed. Please report any bugs you find to us directly and not to other mod authors!
For modders: While I do patch most common patterns of "maximum slot limits" in inventories, I may not be able to catch more advanced ones. Items.AIR.getItemStackLimit(); is your friend!
For modpack developers: Make sure to read the scripting system documentation above. You may also be interested in the list of planned features.
Project icon utilizes Unity textures by CyanideX.
* - Up to about 999 million. However, for reasons, I don't really recommend going above a few (8-16) million, and ideally staying far below that still. (Values far higher than that may cause strange Farlands-esque issues in some mods. You have been warned.)