The VAE is a small separate file which improves the quality of images(Resolve faded colors and ugly eyes)
But if you are interested in what it means: https://www.reddit.com/r/StableDiffusion/comments/zamt9y/what_is_vae/
In general, most models don’t have the vae baked in, so I would suggest equipping a VAE file unless it specifies that it is baked in.
It is recommended to use the vae provided by the model you are using, however personally I prefer to use the Stable Diffusion 1.5 vae, as the colors are quite vibrant
Before (No VAE)
After (With VAE)
To do this, go under settings, stable diffusion and change SD VAE to the vae that you had selected:
In this case, I am using the stable diffusion vae under the Google Colab:
When done, remember to click “Apply Settings” and the vae file will be applied
Personally, I would suggest using Stable diffusion as the vae for all cases except when generating with anything v3.
Stable Diffusion VAE Anything v3 VAE Waifu Diffusion 1.4 VAE 2 Waifu Diffusion 1.4 VAE 2
Stable Diffusion VAE
Anything v3 VAE
Waifu Diffusion 1.4 VAE 1
Waifu Diffusion 1.4 VAE 2