Flux Fill Outpaint
Extends an image past its original frame using flux1-fill-dev. Add a prompt that continues the scene and the workflow fills the new area to match.
- L40S
- Inpaint & outpaint
- Image editing
- Free template
How it works
A LoadImage node brings in your picture, and ImageScaleToMaxDimension limits its size so the padded canvas stays manageable. ImagePadForOutpaint adds empty space around the image and creates a mask for the new area, with feathering to soften the seam.
The model is flux1-fill-dev.safetensors, loaded with a UNETLoader alongside a DualCLIPLoader (clip_l.safetensors and t5xxl_fp16.safetensors) and the ae.safetensors VAE. Your prompt goes through CLIPTextEncode and a FluxGuidance node.
InpaintModelConditioning combines the padded image, mask and prompt into latents, and a DifferentialDiffusion node lets the denoising follow the mask softly. KSampler generates the fill, VAEDecode converts it, and SaveImage writes the result.
Tips
- Write the prompt as a continuation: describe the elements that should appear at the edges and say to keep the same lighting and atmosphere.
- Extend in moderate steps. Very large extensions give the model less context to match.
- Start with a sharp, well-lit source image since the fill copies its style.
- If a seam is visible, increase the feathering in ImagePadForOutpaint.
Run it as an API
You can deploy this workflow on ComfyDeploy as a hosted API endpoint. The inputs listed above become the request fields, so your own app can submit them and receive the finished result without running ComfyUI yourself. The same workflow can also be run and shared from the ComfyDeploy playground in your browser.
What you can use it for
- Turning a square photo into a wide banner
- Extending backgrounds for thumbnails or ads
- Fixing tight crops
- Adding more scene around a subject
Run it in three steps
Open the template
Click Run on ComfyDeploy. The workflow, its custom nodes and models are set up for you on a cloud machine.
Add your inputs
Provide source image and text prompt describing the extension in the playground or the ComfyUI editor.
Run, share or deploy
Run it on an L40S, share it with your team as a playground, or deploy it as an API endpoint.
Frequently asked questions
What GPU does this Flux outpaint workflow need?
It runs on an L40S on ComfyDeploy. It loads flux1-fill-dev with the t5xxl_fp16 text encoder.
How should I prompt for outpainting?
Describe what continues beyond the edges, such as the setting, lighting and architecture, and say to match the existing image.
How do I run it as an API?
Deploy it on ComfyDeploy and send an image and prompt to the endpoint. The extended image is returned.
