How to Blur a Photo's Background on Android (Portrait Mode Without a DSLR)

A blurred background — photographers call it bokeh — does one simple job: it removes visual competition. When everything behind your subject is soft and out of focus, the eye has nowhere else to go, and even a phone snapshot starts to look like it was shot with a proper camera lens.

Optically, this effect comes from a wide aperture and the physics of depth of field — a large sensor and lens letting less of the scene stay in focus. Phone cameras, especially single-lens or older ones, can't produce that optically. That's the gap AI background blur fills: instead of a lens creating the blur while you shoot, an AI model detects the subject after the fact and blurs everything that isn't it.

The process works on a photo you already have — no reshoot required:

1. 1

   Pick a photo

   Open Cutout and choose any photo from your gallery — it doesn't need to have been shot with portrait mode.

2. 2

   Let the AI separate the subject

   On-device AI detects the person, pet, product or object and creates a cutout, isolating it from everything behind it.

3. 3

   Clean up the edges

   Use the Keep and Erase brushes to fix any missed detail — edge accuracy matters here, since a jagged edge next to a soft blur is easy to spot.

4. 4

   Choose the blurred background

   Select the blurred-original-background option. The scene behind your subject softens while the subject itself stays sharp.

5. 5

   Export the result

   Save the finished photo as a high-quality image to Pictures/Cutout.

Cutout gives you four background options after a subject is isolated, and blur is just one of them. Picking the right one depends on what happens to the image next:

• Blurred original — best when you want to keep the context of the scene (a street, a park, a room) but make the subject the clear focus. Great for portraits and everyday photos.
• Transparent — best when the image needs to be placed onto something else later, like a design, a slide or a sticker.
• Solid colour — best for a clean, distraction-free look for profile pictures or product shots.
• Custom image — best for replacing the scene entirely rather than softening it.

• Refine the edge before you blur. The blur only affects the background — a rough cutout edge stays sharp and jagged right next to soft blur, which is the fastest way to spot a fake. A minute with the Keep/Erase brushes fixes this.
• Choose photos with real depth. A subject standing a metre or two in front of the background gives the AI a clearer separation to work with than a subject pressed flat against a wall.
• Watch for stray strands. Hair, fur and thin objects are the hardest edges for any segmentation model. Zoom in on these areas specifically before exporting.

Optical portrait mode uses depth information captured at the moment of the shot — usually from a second camera or a depth sensor — to blur the background as the photo is taken. It only works going forward, on phones that have the hardware, and only if portrait mode was switched on at the time.

AI-based blur works differently: it analyses the finished image after the fact and detects the subject using the same kind of on-device model used for background removal. That means it works on any phone, on any single photo already sitting in your gallery — including photos taken years before AI portrait effects existed.