SLS very sluggish

When dragging Widgets around a screen, there is a terrible lag.
Also, when typing numbers and text into the Inspector it is also very slow.

What do you want to achieve?

A better performing application please.

What have you tried so far?


Screenshot or video



SLS 1.0.3
Windows 10 x64

Please make video about the lag.
Can you also send the project? You can send it in private too to

Do you also see it when you restart SquareLine?

Restarting SLS seems to fix the issue for a period of time before it comes back.
I will capture a video showing the lag the next time I encounter it.

Best Regards


Can you check the RAM, CPU and GPU usage in the Task manager when SLS runs smoothly vs when lags?

Here is Task Manager when SLS is running sluggishly.

Basically I see a lot of lag when typing into the Widget Name field.
If I close and restart SLS it is okay for a while then slows down again.

This is running on an I9-990K with 64GB RAM and an RTX 2060 graphics card.


Thank you, we also started to experience it.


We’ve speeded up SLS a lot, these updates will be included in the next version.

Cool, look forward to the next update :slight_smile:

I am following up on this old topic. I have upgraded my SLS to version 1.2.3 and it is getting very slow at times to respond, particularly in the inspector and hierarchy selections. I am running a Mac Mini M2 Pro and have closed down non-essential applications. Restarting SLS has a temporary effect, but then it slows again. My project has 15 screens and 558 widgets, mostly panels and buttons, with nothing too complicated going on. I am building a prototype UI

We want to build a larger UI project of about 30 screens using SLS and LVGL. However, if the SLS app is not going to be a practical environment for development at this scale, we might have to rethink our approach.