How do I download locally or cache media files in WebGL?

I wish to download texture images from an Amazon AWS server but download them once.
Once I downloaded the texture, I want to read them from local disk or cache, as I don't want the entire files to be held in RAM.
Is there anything like this in WebGL Unity?
I seem to not be able to find any way to do this.
There might be a solution using JavaScript/HTML5 but I am not proficient in that.

 

Assetbundles.
https://docs.unity3d.com/Manual/AssetBundlesIntro.html

 

Doesn't seem to do what I want. I want to download assets, more like... a single character to add.
Do I need to have an asset bundle per character?
Also, can I use any host? Or is this available only on Unity's cloud?

 

You can set up the bundles any way you want, with one or multiple assets in them. Unity's cloud is for building. You will need to place them on your own servers for actual distribution.