About the Magnetic Lasso Tool
The magnetic lasso is for subjects with a clear edge, such as a product, a building or a logo. Instead of tracing every curve by hand, tap points around the edge. Between each pair of taps the line finds the best route along the strongest edge it can see, so the outline hugs the shape even when your taps are a little off. Tap near the first point or press Close shape to finish, then keep the selection and make the rest transparent, or remove it. A soft edge and crop are available too. The result is a PNG with transparency. It is edited in your browser, and your picture is never uploaded. It finds edges from brightness changes, with no artificial intelligence.
Updated October 2026
How to use the Magnetic Lasso Tool
- 1Select an image or drop one on the page.
- 2Tap a first point on the edge of the part you want.
- 3Keep tapping along the edge. The line snaps to the edge between each tap.
- 4Press Close shape, or tap near the first point, to finish.
- 5Choose Keep or Remove, set a soft edge, press Cut out the selection and download the PNG.
How the line snaps
Each pixel gets an edge strength from the change in brightness around it. Moving across flat colour is expensive and moving along an edge is cheap, so the route between two taps prefers the edge. This is the classic live-wire method used in photo editors.
Tapping well
- Start on a clear point of the edge, such as a corner.
- Tap just on or beside the edge. The line corrects small misses.
- Add taps before sharp turns so the line cannot cut across.
- Zoom the page in on a phone if you need more precise taps.
- Close the shape by tapping near the first point.
When to use it
Use it for products on plain backgrounds, buildings against the sky, logos, signs, tools and anything with firm outlines. For a very curved subject, such as a face, a freehand lasso may be quicker. For a flat colour area, the magic wand or the quick selection tool may be faster.
Keep, remove and soft edges
Keep the selection cuts the object out and makes the rest transparent. Remove the selection takes the object out of the picture. A soft edge of one to three pixels makes the cut look natural, and cropping trims the empty space around the object.
Phone and computer
Tapping is easy on a phone because each tap places a point. On a computer, click along the edge. Large images take a moment because edges are found across the whole picture the first time you tap. Magnetic selection snaps to edges, but other selections suit other shapes. Use the Lasso Tool for free-hand outlines, the Polygonal Lasso Tool for straight edges, and the Magic Wand Tool for solid colours. When the cut-out is ready, Make Background Transparent saves it without a backdrop.
Features
- Line that snaps to edges between your taps
- Close the shape with a button or by tapping the first point
- Keep or remove the selection with a soft edge
- Optional crop to the selection
- Transparent PNG at full size
- Private: edited in your browser, nothing uploaded
Frequently asked questions
How does the magnetic lasso work?
It looks at how quickly brightness changes between neighbouring pixels, which is strongest on an edge. Between two taps it finds the route that follows the strongest edges, so the line sticks to the outline of the subject.
Why does it work better with some pictures?
It needs a visible difference in brightness between the subject and the background. A dark object on a light wall works very well. Similar tones, such as a grey cat on a grey sofa, give a weak edge.
How many points should I tap?
Fewer than you would use with a polygonal lasso. On a clear edge a tap every 50 to 150 pixels is plenty. Add more where the outline turns sharply or the edge is faint.
How do I fix a bad point?
There is no undo for a single point yet. Press Start the line again and retrace, using closer taps where the line went off.
How do I close the shape?
Press Close shape, or tap close to the first point once you have three points. The line then snaps back to the start.
What is the difference from the lasso tool?
The lasso follows exactly where you draw. The magnetic lasso corrects your line towards the nearest strong edge between taps.
Does it use artificial intelligence?
No. It uses edge detection and a shortest-path search, both run in your browser.
Is my photo uploaded?
No.