BiRefNet Background Remover
BiRefNet cuts the subject out of an image and returns a transparent PNG, handling hair and fine edges better than threshold-based tools. Free, no account required.
Input
FormImage*
Result
Preview
Illustrative preview, not BiRefNet Background Remover output
$0.008 per image·~5s
What BiRefNet Background Remover is for
BiRefNet Background Remover from BiRefNet starts from a still you upload, then edits it from your prompt. A typical run takes about 5 seconds at $0.008 per image. Use it when you already have a frame and need a new version, not a picture from scratch.
BiRefNet Background Remover is cheap enough that a generation usually fits the free Knowlify plan's credits. A typical run is about 5 seconds.
Pick BiRefNet Background Remover for image editing at $0.008 per image and ~5s. Compare it with Clarity Upscaler, Flux Kontext on the related cards below if you need a different look, speed, or input type.
How to use BiRefNet Background Remover
- 1. Upload the still BiRefNet Background Remover should start from, then write the change or motion in Input.
- 2. Run it. The prompt and file hand off to the Knowlify studio, where BiRefNet Background Remover generates.
- 3. Stay in the studio if you want that frame or clip inside a longer narrated video.
What you need
- A source still (PNG or JPG) for the model to start from.
Example prompt
a cricket batter mid-shot under floodlights, dirt exploding, photoreal photograph, 85mm, natural light, no text, no watermark, no logo, no UI
Frequently asked questions
How do I run BiRefNet Background Remover?
Run BiRefNet Background Remover on Knowlify at /generate/remove-background. Write the prompt on this page and it opens in the studio, where BiRefNet Background Remover generates a still image. The same studio also turns documents into full narrated videos.
Where can I use BiRefNet Background Remover online?
On Knowlify (BiRefNet's model, knowlify.com/generate/remove-background). You do not need a separate playground. BiRefNet Background Remover runs in the studio next to document-to-video.
Can I make a longer video with BiRefNet Background Remover?
BiRefNet Background Remover itself produces a still image. On Knowlify you can take that output, or skip it and upload a document, and generate a full narrated video with a script you can edit.
What do I need to run BiRefNet Background Remover?
A prompt and a source still. BiRefNet Background Remover will not invent the starting frame for you on this mode.
How long does BiRefNet Background Remover take?
Plan on about 5 seconds for a typical run, then whatever queue time the studio has. Video models sit at the high end of that range.
Is this background remover really free?
Background removal is cheap enough to fit inside the free plan's credits. Output is a transparent PNG with no watermark. A free Knowlify account is required.
How well does it handle hair and fine edges?
BiRefNet is specifically designed for high-resolution dichotomous segmentation, so it handles hair, fur, and thin structures noticeably better than threshold or chroma-key approaches.