Sometimes you need just that little more inventory space when your down in the depths of your mines, or maybe even while venturing to new horizons in Minecraft. Either way this mod will give you all the extra space you could ever need and then some. This mod allows you to increase the size of the players inventory as much as you like until either Java runs out of memory or you hit the integer limit of ~2.14 BILLION. If you really want to you can even use the mod in reverse and shrink the players inventory or remove it all together! There is even options that allow one to earn their new slots with customizable amounts of XP levels.
WARNING: Inventory Tweaks:
Due to one or more programming oversights in Inventory Tweaks transferring/sorting items can result in Minecraft locking up in an infinite loop. I recommend installing an alternative version that has these issues fixed among others.