comfyui-workflows/models/flux/flow-upscaler/README.md

Flow Upscaler

Summary

Fast latent upscaler for the FLUX.2 family. It takes existing FLUX latents and upscales them in latent space, so you can push images much larger without relying only on classic pixel upscalers.

Model Family

• flux

Status

• imported-only

Source

• Original page: https://github.com/tensorforger/comfyui-flow-upscaler
• Workflow file: https://raw.githubusercontent.com/tensorforger/comfyui-flow-upscaler/main/workflow.json
• Original author: TensorForger
• Date imported: 2026-08-08

Developer notes

• The author positions this as a fast latent upscaler trained in Flux.2 latent space.
• The model is trained for 2x upscaling, but multiple passes can be chained for much larger outputs.
• The README recommends the tiny Flux.2 VAE (taef2) for 2048x2048 and above because the original VAE becomes impractical at high resolutions.
• The workflow included in the repo is the demo path the author expects people to load first.

Our notes

• This is one of the most practically useful imports here because it solves a real workflow problem instead of just offering another generation variant.
• It looks especially relevant if you end up using FLUX.2-klein or other lighter FLUX-family generation paths and want cleaner high-res finishing.
• It is more specialized than a generic Ultimate SD Upscale graph, which is a good thing if you want something clearly tied to the FLUX latent stack.

Required custom nodes

• comfyui-flow-upscaler
• rgthree-comfy for Image Comparer

Built-in / core nodes used

• Flux2Scheduler
• EmptyFlux2LatentImage
• standard CLIP / UNET / VAE loaders
• sampler selection and advanced sampler nodes

Notes

• Model weights are separate from this workflow and need to be downloaded from the source repo's linked Hugging Face page.
• Best use: upscale a good FLUX-family image after the composition is already right.