Developer Console Causes Massive Memory Leak

Reproduction Steps
To reproduce, simply open the console in-game and go to the Client/Memory section. Scroll up and down a little for good measure. After a minute or two, observe how high LuaHeap is.

System specs:
GPU: RX 5700
CPU: Ryzen 7 3700x
Memory: 16gb 3200mhz

Expected Behavior
I expect that using the console would not impact memory count very much, if at all. The console itself should not impact the performance of the game.

Actual Behavior
After playing my game normally for about 10 or so minutes, I open the console to check the memory. I observe a normal amount of memory (~520 MB) immediately after opening the console. After looking at client memory for a minute or two, I notice the total memory up to 700 MB with near 150 in LuaHeap.

This happens with every script in my game disabled, and even in an empty baseplate. In fact, the baseplate’s LuaHeap memory rose to 250 MB after about 20 seconds of being in the console.

Picture of PlaceMemory immediately after opening console:

Picture of PlaceMemory after being in console for 1.5 minutes:

Issue Area: Engine
Issue Type: Performance
Impact: High
Frequency: Constantly
Date First Experienced: 2021-11-27 00:11:00 (-05:00)
Date Last Experienced: 2021-11-27 00:11:00 (-05:00)


I noticed this issue as well. I didn’t understand why but LuaHeaps was taking so much memory and continuing to rise quickly over time.


This appears to be due to Roact trees being left in the heap for some reason. Probably an issue with core scripts and not the engine itself.

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It seems to be an issue to be addressed immediately. The issue appears to be clientside and it is crashing lower-end devices with low ram memory. I noticed an increased crash rate out of nowhere on low end mobile user.

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This is happening to me in a baseplate with only 100 parts and no scripts.
PC Specs:

  • Ryzen 9 5900x
  • 32 GB 3600 MHZ Ram
  • Rtx 3080
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I think this has correlations with the core health ui being broken, some people have mentioned it there. Read: Health CoreUI is broken - #31 by pozzzy333


follow up to this; roblox has taken action and is releasing a patch next week:


Roblox fixed the warnings in the console. But the memory leak still remains

hm, interesting. i don’t know what it could correlate with then…

I think it is gone since I do not get crash report anymore for a while.

This issue is still occurring. I have been unable to properly debug LuaHeap related memory leaks or even see if they exist in my games due to the Developer Console memory leak. Was there an update posted on the status of this? I’d love to have this issue be fixed as soon as possible so we can get back on track eliminating memory leaks.

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Hi there,

In case you were not aware, Roblox team members are on break from work for the holiday seasons. As such, they are doing more important things at the moment (eg. spending time with family or doing other off work activities). This means that the team doesn’t have access to the internal tools required to fix this issue, nor do they have the time to do so.

Fear not though! Roblox team members will be back to work soon. Once they’re back to work, an internal report may be filed on this issue and the bug here will be patched. Thank you for still acknowledging this issue!

– ghidras


Hello, everyone! I tried to reproduce the issue myself, but I was unsuccessful. @vastqud can you DM me a repro-place? I would very much appreciate that!


No problem, I just DM’ed you the file and the link to the experience I was using to play online.


I’m having the same issue in my own place, I checked in the memory breakdown from the client and found that there’s 1 specific section constantly consuming lots of memory and then dumping it into the LuaHeap:

There’s a second one also taking up memory though not as much as the first one: Image


This still seems to be a problem, the client ‘LuaHeap’ continues to jump by around 20-30 every so often. I’ve disabled and removed all of my client scripts and it still jumps & slowly increases. This is making it very difficult to resolve my own issues related to memory.

I’m still quite new to the whole idea of memory leaks, but this did topic seems to fit the issue.

Client Version: 0.509.0.5090219 (6808cd)
Client CoreScript Version: 534595812.3047


Lua Heap is actually not the issue for me, it’s actually untracked memory, and it spiked significantly. LuaHeap rose a bit but not as much as untracked memory.


It has brought to my attention that the following section appears to skyrocket when you scroll in the Developer Console. That’s all I found and I hope it helps.

Here’s a video example that may proof my thesis (Unfortunately the file is too large to upload in full quality)

Click this link to download the original MP4 (This is a Discord Attachment link)


Hello! This issue is being worked on. I will update you once this is fixed.


So has this been fixed yet? I’ve been getting 300MB+ on my LuaHeap and now I’m not sure if it’s the result of the game or the console.