Sketch Up running slowly–April 2020

Hello Sketch Up community,
I’m brand new to Sketch Up; have been trying to learn with the tutorials as well as mucking about with my trial SU Pro. I’m using this to do concert lighting plots. I have a new MacBook Pro 16" with more than enough speed and memory, but am still having some lagging issues. I think it’s because I’m importing all kinds of things/models (musicians, trussing, lighting fixtures) from the Warehouse. My file size is already closing in on 200MB, and I’ve barely started putting lights in the drawing. What do I need to do to make my drawings smaller? Is there some process I need to perform to make what I import smaller? If I keep adding more stuff from the Warehouse, I’m afraid the machine will totally bog down. Any advice/help will be greatly appreciated.


Hi Joel

One thing I do when using any models from the Warehouse is to firstly import them into a separate new Model.

They can then be checked and cleaned up, removing anything not required, such as unnecessary details that will not be seen in your final model. Check for any hidden geometry that may be present but not required.

Some Models on the Warehouse have a very large amount of detail, modelled with many faces and edges, creating a large amounts of geometry, increasing the file size. By importing the Model into a blank new file, you can see how much detail is shown and can then eliminate what is not needed for your Model. For example, if the Light Fitting has all the screws and washers and wires in, are these really relevant or required in your Model?

Then do a Save As, saving it into a suitable location. Finally do a Purge to get rid of any redundant Layers and Styles, then a final Save.

Also make use of Components for repeated elements, such as Light Fittings, for example.

This should reduce the File Size of the Model, which can then be imported into your Model.



The best models are those you build yourself.
Learn to build great models that perform well instead of using SketchUp as if were only a kit comprised of other users’ models.

How do I make SketchUp run faster? — SketchUp Sage

Making a detailed model in a lightweight way — SketchUp Help

Hey George,

Thank you for the tips. I’ve read the sections you suggested, and still have questions.

If I take something from the Warehouse, can I apply the softening, smoothing, hiding of geometry on the chosen model or is it already set and can’t be changed? I see that making one’s own models is likely the best way to go, but I’m not sure I have the tools to draw a lighting fixture. I’ll give it a try. I suppose this is where one applies the softening, smoothing, and hiding of geometry.

Is there any kind of Find/Replace functions, whereby if I make a much smaller fixture, I can substitute it for the ones already place in the drawing?

It also seems that on certain models, I can delete the nuts and bolts; even when I Edit the Component. If they are in a group, does that also prevent me from editing the component? How would one ‘Ungroup’ them if I want to make changes?

What is the optimal size range of a drawing? Is there a point, such as 200MB, where the size starts to adversely affects the program?

Seems like I have some large models in the drawing. When I go to the Components box, I try to scroll down and delete them, but it doesn’t allow me to. Do I need to do all of the deleting in the drawing? Why is this grayed out here? Even when I delete them from the drawing, I still can’t delete them from the Components list. And it seems that it only changes my file size when it’s deleted from the everywhere.

Lastly, where can I find Purge?

Those are enough questions! I appreciate the help you can provide.



Joel Reiff


There’s nothing magic about the models you download from the Warehouse. You can edit them any way you like in SketchUp. Any edge can be hidden, smoothed or softened. You can use the eraser tool with modifier keys to hide, smooth & soften, unsmooth & unsoften. Read about that here:

Yes, if they’re both components. In the components window, right click on the big one and choose “Select Instances” then right-click on the small one and choose “Replace Selected”. Every big one will be replaced with a small one with one click. If some of them are inside other groups or components, the select instances part won’t work in one click, but this will still save you a lot of work.

I’m not really sure what you’re asking here. Being inside a group wouldn’t prevent you editing the component in there. You can have multiple levels of nesting groups inside components inside groups, etc.

There’s no set file size as file size doesn’t directly correspond to how much work your computer has to do to display the model. You could have a 1MB file with thousands of copies of one component that would slow SketchUp down a lot. The limit would depend on your hardware and how patient you are to put up with waiting. This pointless file has 4000 copies of one component, is 1,003,082 bytes and with profiles on takes 2 or 3 seconds to display the profile edges.

tri.skp (979.6 KB)

Purge (for components) is in the Components Window:

Purge Unused

There’s also a “Purge Unused” button in Window->Model Info->Statistics. That will purge unused materials too and get your file size down but obviously don’t use purge if you have a component or material that you mean to use later and don’t have any actually in the model. Those statistics might give you a better idea of when your model is getting too big e.g. you might find a million edges is too slow.

Yeah, it was quite a lot of questions, I missed one:

Maybe you’re left clicking on the component so that there’s one ‘in your hand’. The mouse cursor will change to four arrows. If you move the mouse away from the components window, there’ll be one of those components stuck to the mouse cursor. If you have picked one up by mistake, just press Esc to clear it. Don’t left click first, just right-click and you should be able to delete the component. If there’s some in your model you’ll get a warning.

File size is a poor indicator of model performance.
Your modeling technique has a tremendous impact upon model performance.
And while the notion that bleeding edge hardware should easily compensate for poor technique is appealing, the simple fact is, it won’t.

The folks at SketchUp and many others have created a wealth of free learning resources.
A few hours invested in learning will save you many days of frustration.
Undertake an organized course of independent study and practice.

Here’s a good place to start:

You’ll find links to many other learning resources in this list:
SketchUp Learning Resources.pdf (148.2 KB)

Hey George,

Your help and advice has been EXTREMELY helpful and I can’t thank you enough for it. It’s gotten me over the initial hump with this program, which I know plan to purchase after my trial period runs out next week.

I do have a couple more questions, if you’d be so kind to answer for me.

  1. Is it possible to ‘Color By Tag’ just one Tag? I don’t want the entire drawing to color by tag, just one tag.

  2. I see where you can get rid of the blue/grey horizon, but is there a ‘black’ to show kind of a ‘lights out’ look?

That’s about it. I’m going to hit the tutorials hard, but thanks so much for getting me going.



Joel Reiff