Question: I have a scene in blender when exported as a gltf file it is 155 megs in size.
I've tracked down the entire model and found that the following objects which are 4 are 100 megs.

[![enter image description here](https://i.stack.imgur.com/gcBJJ.jpg)](https://i.stack.imgur.com/gcBJJ.jpg)

When I view it doesn't look too complex. By this I mean it doesn't look like a complicated mesh but obviously something is going on to why it's so big in size. It's just the inside of the building so I don't need high end texturing etc. I'm not sure if the size comes from the "complexity" of the object or if its' texturing etc that makes it so large. How would I be able to reduce this in size?

Answer: 
Blender has a built-in "Statistics" overlay that I often find helpful:

[![Blender statistics screenshot](https://i.stack.imgur.com/Un7HJ.jpg)](https://i.stack.imgur.com/Un7HJ.jpg)

For the case of analyzing a glTF like this, I recommend exporting from Blender using the option called `glTF Separate (.gltf + bin + textures)`. You can look at the resulting file sizes individually. You can also load them into [VSCode](https://code.visualstudio.com/) with the "glTF Tools" extension installed, and get a detailed breakdown:

[![VSCode screenshot](https://i.stack.imgur.com/g84pm.png)](https://i.stack.imgur.com/g84pm.png)

[Disclaimer, I'm a contributor to the VSCode extension for glTF.]
I doubt it is the mesh that makes the gltf file so heavy, since the objects are barely 1300 tris.

Here is something you can do if you need only the mesh for the gltf file :

First of all, you have a few options when it comes to exporting to gltf format :

[![enter image description here](https://i.stack.imgur.com/KoL90.png)](https://i.stack.imgur.com/KoL90.png)

The first one, `glTF Binary (.glb)`, is the default and it packs all the data in binary format in one file. If this is the on you chose, it may be the reason for the big file.

The second one, `glTF Embedded (.gltf)`, is the same as the first one but the data is packed in JSON format.

The last one, `glTF Separate (.gltf + bin + textures)` will save multiple files and will output a more lightweight `.gtlf` file so you can try this one to see if it solves the problem.

You can also chose which data you export in the `Include` setion :

[![enter image description here](https://i.stack.imgur.com/Bqbyp.png)](https://i.stack.imgur.com/Bqbyp.png)

By ticking `Selected Objects`, for example, you can limit your export to only the objects that you selected.

You can also check the `Geometry` section where you can chose to apply modifiers, export UV's, materials and so on.. Some of the options are enabled by default so you should check if there are some that you don't want.

Under `Animation` section, you also enable/disable exportation of shape keys, weight paint data and so on..