Blur Background

Blur the background of a photo like portrait mode

A blurred background makes the subject of a photo stand out — it is why portrait lenses and phone “portrait mode” are so popular. This free tool lets you blur the background of any existing photo: an AI model finds the person or object, the background is softened as much as you like, and the subject stays perfectly sharp.

It is useful for profile pictures taken in a messy room, product photos on a busy table, pet portraits in the park, or hiding what is behind you in a picture before you share it. Everything happens in your browser, so the photo is never uploaded; only the AI model is downloaded the first time and then kept in your browser’s cache.

How to use the Blur Background

1. Pick the AI model: “People & portraits” for people, “Products & objects” for things, pets and full-body shots.
2. Drop your photo onto the upload box or paste it with Ctrl+V. Wait for the progress bar the first time while the model downloads.
3. Set “Background blur” — around 30 for a natural portrait look, 70 or more for a dreamy, heavily defocused background. Darken the background a little with “Background brightness” to make the subject pop.
4. Check the edges. Raise “Edge softness” for a gentler transition, and use “Restore” or “Erase” to paint over anything the AI kept sharp or blurred by mistake.
5. Choose JPG, PNG or WebP and press “Download image”.

Blur Background features

How the portrait effect is made

A real camera blurs the background because of depth of field: with a wide aperture (a small f-number such as f/1.8) and a subject close to the lens, only a thin slice of the scene is in focus. Phones fake this with depth sensors or AI. This tool takes the AI route. First the model produces a mask that says, for every pixel, how much it belongs to the subject. Then the background is blurred with a Gaussian-style filter in which each pixel is weighted by how much it belongs to the background, and the result is divided by the blurred weights. That normalisation is the important trick: a plain blur would mix the subject’s colours into the background and leave a glowing outline around the person.

Finally the sharp subject is laid back on top using the soft mask, so hair and fur blend naturally into the blur. The blur is computed on a reduced copy of the photo for speed and scaled up, which is invisible because blurred areas contain no fine detail.

Tips for a convincing result

• Moderate is more believable. A strength of 25–45 looks like a fast lens; very strong blur looks like a studio backdrop.
• Watch the ground. In a real photo, the floor near the subject’s feet is nearly sharp. This tool blurs all of the background equally, so for full-body shots a lower strength often looks more natural.
• Keep held objects sharp. A phone, cup or bag in someone’s hand may be classed as background. Paint over it with “Restore”.
• Start with a sharp photo. Blur can’t fix a subject that is already out of focus; it only makes the difference clearer.
• For privacy, go further. Blur makes a background less distracting, but text and faces can still be guessed at low strengths. To hide them properly, use Pixelate Image or replace the background entirely with Change Background.

Models and limitations

The models are open source and permissively licensed: MODNet (Apache 2.0, 13 MB), U²-Netp (Apache 2.0, 4.6 MB) and the MediaPipe Selfie Segmenter by Google (Apache 2.0, 0.25 MB). They run with ONNX Runtime Web and MediaPipe in WebAssembly. Like every automatic cut-out, they find edges hardest where the subject and background share a colour, around wispy or curly hair, and with transparent things such as glasses and veils — expect to touch those up with the brush. For a cut-out with no background at all, use Remove Background; for general softening of the whole picture, try Image Filters.