This started as a supporting tool for a Home Assistant floorplan card generator I am building. Property floorplans from sites like Zoopla come loaded with agent branding, room labels, and white backgrounds, none of which belong in a dashboard asset. I needed a clean extraction pipeline, nothing on the market did the job without paying for a third part tool. I didn't think I needed that, so I built one. Once it was working I realised it was useful enough to release standalone.
Extractly is a six-step browser tool that runs entirely client-side. It uses colour mathematics rather than machine learning, comparing pixels against a sampled reference using perceptual weighting tuned to how the human eye reads colour. It works best on flat-colour images: floorplans, diagrams, logos, icons. Photographs can be processed but need more passes.
The pipeline covers content redaction, background removal with live tolerance preview, protected-palette colour cleanup, manual blemish erasing, and flexible crop export as transparent PNGs. It works on desktop and touchscreen devices.
If you want to use the code and build it into something you are working on, feel free. No build tools, no dependencies, no server. Just three files.