FAQ

Common questions about Roblox script performance. To go deeper on any answer, the linked guides in this section cover each topic in full.

Why is my script causing lag?

The usual cause is a loop without a wait, or heavy work running every frame. Add task.wait() to continuous loops and throttle expensive checks — reducing script lag is the full guide.

What is a memory leak?

Memory that is allocated and never freed — typically instances or event connections that are never cleaned up. Over a long session it degrades performance and can crash the game. Fixes are in managing resource usage.

How do I find what's slow?

Profile it. Roblox's MicroProfiler shows where each frame spends its time, so you fix the real hotspot instead of guessing. See profiling your scripts.

Does running a script hurt my FPS?

A well-written script has negligible impact; a poorly-written one (tight loops, no cleanup) can tank your FPS. The same optimisation habits apply whether you are writing or evaluating a script — see optimizing script efficiency.

Why does it run fine for me but lag for others?

Multiplayer load and network cost. Code that is fine solo can struggle with many players or chatty RemoteEvents — test with multiple clients (script performance testing) and follow best practices for multi-player scripts.

How do I know if my optimisation worked?

Measure before and after with the same test. understanding performance metrics and profiling your scripts together tell you whether the numbers actually improved.