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Documentation Index

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The Upscale or Variation (UOV) feature lets you either enlarge an image beyond its original resolution or create alternative versions of it with varying degrees of change. You can use it on any image — not just ones generated by Fooocus — making it a general-purpose post-processing and variation tool.

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Accessing UOV

Go to Input Image → Upscale or Variation tab. Upload your source image, choose a UOV method, and click Generate.

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UOV Methods

Fooocus provides six UOV modes:

Disabled

UOV is turned off. The input image tab has no effect on generation. This is the default state.

Vary (Subtle)

Generates a variation of the input image with small, subtle differences — different lighting, minor detail changes, or slight compositional shifts — while preserving the overall scene.

Vary (Strong)

Generates a more significant variation. The output will share the general subject and composition of the input but may differ noticeably in style, details, and colors.

Upscale (1.5x)

Upscales the image to 1.5× its original resolution using the Fooocus upscale pipeline, adding fine detail during the process.

Upscale (2x)

Upscales the image to 2× its original resolution. More detailed enhancement pass compared to Fast 2x.

Upscale (Fast 2x)

A faster 2× upscale that skips some of the enhancement steps. Good for quick results when maximum quality isn’t required.
UOV works on any image, not just images generated by Fooocus. Upload a photo, an illustration, or output from another tool and apply upscaling or variation directly.

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UOV with Enhancement Pipeline

When using the Enhance tab alongside UOV, you can control when the UOV step runs relative to enhancement passes:

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Processing Order

OptionBehavior
Before First EnhancementUOV runs first, then enhancement passes are applied to the upscaled/varied result
After Last EnhancementAll enhancement passes complete first, then UOV is applied to the final enhanced image

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Prompt Types for Enhancement UOV

When UOV is used in the enhancement pipeline, you can choose which prompts apply during the UOV step:
OptionBehavior
Original PromptsUses the main generation prompts during the UOV step
Last Filled Enhancement PromptsUses the prompts from the most recently configured enhancement pass

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Describe Feature

The Describe tab (also under Input Image) is a reverse-generation tool: upload an image and Fooocus will generate a text prompt that describes it. This is useful for:
  • Understanding what prompts could recreate a similar image
  • Building a starting prompt for further variation or upscaling
  • Learning effective SDXL prompt structures
Two describe modes are available:
Type: PhotographOptimized for real-world photography. Generates a prompt describing camera settings, lighting, subject, and scene in photographic terms.

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Step-by-Step Upscaling Workflow

1

Open the UOV tab

Go to Input Image and click the Upscale or Variation tab.
2

Upload your image

Drag and drop or click to upload the image you want to upscale or vary.
3

Select a UOV method

Choose from Vary (Subtle), Vary (Strong), Upscale (1.5x), Upscale (2x), or Upscale (Fast 2x) depending on your goal.
4

Generate

Click Generate. For upscaling, the output will be at the target resolution. For variation, a new version of the image is produced.
Upscaling uses dedicated upscale models stored in Fooocus/models/upscale_models/. These are downloaded automatically on first use.

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