FluxSR: One-Step 4x Super-Resolution LoRA for Flux.1-dev

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FluxSR publishes its one-step 4x real-world super-resolution LoRA for Flux.1-dev, with training and inference code plus a ready community ComfyUI node pack.

<strong>FluxSR</strong> is a one-step real-world image super-resolution model built on Flux.1-dev. The ICML 2025 project published its training, inference and evaluation code together with the model package on October 13, 2026, so the weights can be run outside the paper for the first time.
FluxSR compared with other real-world super-resolution methods

From the project repository: FluxSR reconstructions next to other one-step and multi-step super-resolution methods.

What FluxSR does

Multi-step diffusion super-resolution is accurate but slow, and earlier one-step variants inherit the artefacts of whatever teacher they distilled from. FluxSR keeps Flux.1-dev as both the teacher and the base model and adds three pieces on top of it:

  • Flow Trajectory Distillation (FTD) distils the multi-step flow-matching model into a single sampling step, so one pass through the transformer produces the 4x image.
  • TV-LPIPS replaces a plain perceptual loss with a total-variation weighted variant, which the paper uses to push the reconstruction towards realistic texture instead of smooth averages.
  • Attention Diversification Loss (ADL) is a regulariser that lowers token similarity inside the transformer, which is where the high-frequency speckle in one-step outputs usually comes from.

The result ships as a LoRA adapter rather than a full checkpoint. The adapter is 717 MB, the rank and alpha are both 64, and inference runs at timestep 350 with guidance 4, all read from the bundled training_config.json.

FluxSR pipeline

The FluxSR training pipeline: a Flux.1-dev teacher generates the training pairs, and the LoRA student is distilled to a single step with TV-LPIPS and ADL.

What is in the release

FileWhat it is
pytorch_lora_weights.safetensorsThe FluxSR transformer LoRA adapter (717 MB)
training_config.jsonTimestep, guidance and LoRA rank/alpha used at inference
t5_embedding.pth, clip_embedding.pthFixed text embeddings the adapter expects
prompts_10k.jsonThe 10,000 prompts used to generate the training pairs

The repository documents the full loop, not just inference. Training data is generated with the Flux.1-dev teacher at 50 steps and guidance 3.5, storing paired noise, teacher latent, decoded image and seed, and scripts/evaluate.py reports PSNR, SSIM, LPIPS, DISTS and MUSIQ against ground truth when it is available.

FluxSR quantitative comparison table

Table 1 of the paper: quantitative comparison against other real-world super-resolution methods.

FluxSR on RealSet65

Table 2 of the paper reports the same comparison on RealSet65.

FluxSR qualitative comparison

Qualitative comparison from the paper: FluxSR against other super-resolution methods on real-world low-resolution inputs.

Running it in ComfyUI

The project ships no ComfyUI node itself, but a community pack appeared the same day. JohnDopamine posted a FluxSR node pack in the Banodoco #flux channel on October 13, 2026 (version 1.0.1 fixes the T5 and CLIP embedding paths), and reported two runs on a machine with about 84 GB of usable VRAM:

InputOutputTime
446 x 4481784 x 17923.18 s
688 x 8642752 x 345634.91 s

The pack runs Flux.1-dev with the LoRA plus the two fixed embedding files from the Hugging Face package, so anything that can already run Flux.1-dev can run it. Batched and tiled modes exist for larger inputs, and the inference script exposes --offload sequential and --vae-tiling for lower-memory setups.

The node pack currently lives in the community channel as a zip rather than in a repository, so installation is manual.

Availability

The LoRA weights, fixed embeddings and training prompts are on Hugging Face, and the training, inference and evaluation code is on GitHub. The base Flux.1-dev weights have to be downloaded separately after accepting their access conditions.

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