Flux.2 Klein + Refiner — Clean, Fast, No Nonsense
I'll be honest: I was almost ready to give up on Flux.2 Klein.
I spent an entire night downloading and testing workflows I found online — some popular, some less so — and none of them worked the way I needed. Generation times were absurd, sometimes hitting 400 seconds or more. On top of that, I kept getting images at resolutions I never asked for, with no upscale nodes in sight and no clear explanation. I was going crazy trying to fix issues I didn't even fully understand.
At some point I thought: maybe this is just how Flux.2 Klein works. But something didn't feel right. So instead of giving up, I built my own workflow from scratch — adapting it to the way I actually work.
Turns out the answer was simpler than I expected.
What this workflow does
This is a clean, straightforward Flux.2 Klein workflow with an optional SDXL refiner pass. No bloated node chains, no mystery outputs, no hidden upscaling. What you set is what you get.
Generation times I've achieved:
Without refiner: 20–30 seconds per generation
With refiner (SDXL 1.0 DMD): 35–40 seconds
(obviously based on my hardware, so your results may vary)
Resolution: fully customizable via a dedicated node — I personally use 1536×1920, but you can set whatever you need.
How the refiner works
After Flux.2 Klein generates the base image, a second KSampler with an SDXL 1.0 DMD checkpoint refines it at low denoise. Nothing exotic — just a classic refiner setup that adds detail and polish without rebuilding the image from scratch. You can run it or skip it depending on your needs.
Why am I sharing this?
Because I wasted hours on workflows that looked impressive but performed terribly, and I don't want the same to happen to you. This one works (at least for me :)... ). It's not fancy, but it's fast, predictable, and the results speak for themselves.
If you try it, let me know what you think. And if you use it for portraits or lifestyle shots, I'd love to see what you create.
All sample images were generated with this workflow. No post-processing.
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FAQ
Comments (11)
The folder I download is empty...
This is weird, I'll check as soon as I get home. Is it really completely empty with nothing inside?
@ShinobiSat for some strange reason, it is not downloading corrctly. I get a flux2KleinRefiner_v10.widmwJZF.zip.part file.... then not finishing. Happened yesterday and today agin. Not happening with other .zip files I download....
@travahaka No, I'd say it's not the right file... I tried to download it and it downloads correctly and the workflow works. Maybe I'll try to re-upload it.
@travahaka Hi, I've posted an updated version of the workflow. Try downloading that one and let me know if it works.
@ShinobiSat It downloaded for me just now and extracted correctly
@antigen3 Great news! Good luck! 😉
@ShinobiSat It is a good workflow, I had issues with the Save image node so I replaced it (worflow would error out when it reached that point and I couldn't figure out why) But you are correct it is a pretty fast and nice workflow
@antigen3 Thanks, I'm glad you like it! Yes, I think the issue with the “Save image” widget depends on the version of ComfyUI. unfortunately that node is no longer supported in some versions. I hadn’t noticed because I had an “older” version of ComfyUI and it was working, but last night I updated and it stopped working for me too. You can safely use any “Save Image” node; if you want a node that also saves the metadata, there are various forks of that node I had included, but you can’t install them directly from the manager—you have to install them manually via Git
@ShinobiSat Yes the issue with nodes becoming un supported is one of the many pains with comfy.
-In regards to the saving - I normally set up a compare node with a save selector so I can choose which image to save (with or without the refiner depending on which looks best) so I only noticed the issue with your workflow when I was doing the first test to see if anything was broken before I started making changes LOL
But it is a very good workflow and is fast becoming the basis of all my flux2 stuff and chunks of it will probably end up in my QWEN workflows as well
Works fine for me2 now. Thank you!