Fixing Choppy or Laggy Item Animations in Smooth Swapping

The most common complaint about this mod is that it looks stuttery on lower-end machines. The cause is almost always frame rate, but a few other things can make it worse.

Confirm It Is an FPS Problem

Watch your FPS counter while shift-clicking a stack. If the number dips below roughly 30 during the animation, that is your culprit. The mod interpolates item positions per frame, so fewer frames means fewer positions and a visibly steppy slide.

Steps to Improve It

1. Lower render distance and simulation distance.

2. Turn off smooth lighting, fancy leaves, and clouds.

3. Reduce the number of entities and particles around you (mob farms and heavy redstone are common offenders).

4. Allocate more RAM to your instance if you are near the limit — stuttering from garbage collection also breaks the animation.

5. If you use shaders or heavy optimization mods, test with them off to isolate the cause.

When to Just Disable It

If your hardware simply cannot hold a stable frame rate in busy areas, consider turning the mod off for those sessions. A choppy animation is more distracting than no animation, and the mod is purely cosmetic — nothing about your inventory behavior changes.