Stability release a VAE model for generating images with more details.

Here's how you can launch Stable Diffusion Web UI with VAE model.

Command

# macOS Apple Silicon
./webui.sh --precision full --vae-path "/Users/username/stable-diffusion-webui/models/VAE/vae-ft-mse-840000-ema-pruned.vae.pt"
# nvidia
./webui.sh --vae-path "/Users/username/stable-diffusion-webui/models/VAE/vae-ft-mse-840000-ema-pruned.vae.pt"

Reference

Answer to Loading VAE models