Detailed comparison between standard VAE and the UltraFlux VAE: https://imgsli.com/NDM1MTI2

This vae is not made by me, I am simply re-uploading the vae from this awesome project https://huggingface.co/Owen777/UltraFlux-v1!!!

From my testing it improves the sharpness of any model using the flux vae (flux based models, Zimage, etc).

In rare cases it might look a little over sharpened but from my short testing it looked pretty good.

Links to the project from which this vae originates from:
https://huggingface.co/Owen777/UltraFlux-v1
https://github.com/W2GenAI-Lab/UltraFlux/tree/main

I should have clarified from the start, but basically as vladulidlo has mentioned it's best to use this VAE on a second pass after upscaling. In my opinion it is still worth using in simple 1 pass workflows too (which is why I didn't bother overcomplicating stuff) but if you pixel peep and the oversharpening bothers you then use a 2 stage generation workflow for better results.