Background removal
Background removal makes the background transparent and keeps only the character or subject. The result is a PNG with a transparent background, saved as a new version of the image (marked “No BG” in the version list). Transparent areas are shown as a checkerboard when comparing.
Getting a model
Section titled “Getting a model”The first time, a model needs to be downloaded (only once). After choosing “Remove BG” as the refine mode, you can download:
| Model | Description | Size |
|---|---|---|
| Anime characters (ISNet) | Trained on anime character images; fast | about 204 MB |
| General (BiRefNet lite) | Works for photos, objects and illustrations; handles fine edges such as hair well; a little slower than the anime model | about 178 MB |
If a download is interrupted, press the button again to resume. If automatic download fails (for example, when antivirus software blocks it), press “Download manually”, open the shown address in your browser, put the file in the shown folder (no need to rename it), and press “Check again”.
Using your own model
Section titled “Using your own model”Put an IS-Net or BiRefNet .safetensors model in rembg in CoCo’s model folder and press “Check again”; it appears in the model menu. Models fine-tuned by others work too; files that can’t be used are listed with the reason.
Basic steps
Section titled “Basic steps”- Choose “Remove BG” as the refine mode.
- Choose the “Model” and “Edges”.
- Press “Remove background”.
| Edges | Description |
|---|---|
| Soft | Uses the soft edge from the model; fine details such as hair look more natural |
| Crisp | Narrows semi-transparent edges; cleaner edges, but fine hair may look harder |
With your own model, if the result looks wrong, try switching “Type” between “Anime” and “General”.
Afterwards
Section titled “Afterwards”- Press “Edit” to add a background or text in Output.
- Transparent images can be upscaled directly; the background stays transparent.
- Select several images in the library and press “Batch refine” to remove backgrounds together.
Comparing the two models
Section titled “Comparing the two models”Measured on 1024-pixel images, each takes about 0.3–0.5 seconds. BiRefNet gives crisper edges and also catches people in the distance; ISNet sometimes leaves background objects such as flowers or pillars.
Models you no longer need can be deleted under “Model file” to free up space.