How to reduce texture resolution

How do i reduce texture resolution so that i can reduce my build size. In unity i can just do that by selecting texture and chaning from 2k to 512 but i dont see any option in unreal. Is there anything similar??

Open up texture and change lod bias setting from 0 to desired setting. It will display the new texture size above and should reduce size permanently when cooking/packaging build.

Can you explain more?

Each texture has an LOD0, original size. So if your texture is 2048x2048, when you look at the texture asset in Unreal, you ought to see a LOD Bias setting of 0. If you set this to 1, it will reduce the level of detail, guessing it will make it 1024x1024.

What this tells unreal is that the original texture is always going to be 2048x2048, but since you forced a base LOD of 1, it’s always going to be loaded and run at 1024x1024 at best.

This lets you use really large textures, say if you didn’t make them yourself, but still tell unreal to essentially scale it/them down to your desired size.

To go into more detail:
Double click a texture in the content browser (an icon with a red bar at the bottom)
This will pop a window with texture details
You’ll see the imported size (top right) ex: 4096x4096
You’ll see Resource size (top right) ex: 21,846 Kb
You’ll see the number of mips (top right) ex: 13
FYI: Each level of mips cuts the size in half (so mip 1 is 2048x2048, or 1/4 of the data size)
Scroll down to Level of Detail
Here you can change the LOD Bias
When you change it you’ll see the Resource size drop
As well as the Max In-Game texture size (top right)

So if your target is 2k textures you can set 4k bias to 1, 8k bias to 2.
Unfortunately, I don’t personally know of a way to do it other than stepping through each texture. That doesn’t mean that it doesn’t exist.

Related Question. If I set an 8K texture to a bias of 2, does it take the same amount of space on disk, only savings is in RAM?

What about when I package/bake everything?