How to Upscale AI Images in ComfyUI to 4K (2026) - Ultimate SD Upscale Tutorial | Floyo

Run workflows in three seconds, no installs: https://floyo.ai. Most open-source AI models top out around 1024×1024 - sharp, but nowhere near 4K. In this chapter, we'll walk you through the two upscaling methods we actually use in ComfyUI: a three-node lightweight upscale you can run in seconds, and the full Ultimate SD Upscale pipeline that gets you to cinematic 4K without visible tile seams. This video was created by ‪@sebastiankamph‬ in collaboration with Floyo. By the end of this chapter, you'll know exactly which method to reach for, how to read every setting on the Ultimate SD Upscale node, and the one parameter (denoise) that quietly decides whether your final image looks pristine or stitched together. ▶ Browse 1000+ ready-to-run workflows: https://floyo.ai/workflows ▶ Book a demo for teams & studios: https://floyo.ai/enterprise 👇 Drop a comment: which upscaler do you reach for first? #ComfyUI #UltimateSDUpscale #AIArt #StableDiffusion #Floyo