How to Change Your Webcam Shape in OBS: Circles, Squares and Custom Frames

The short answer

OBS Studio changes the shape of a webcam feed with filters added to the camera source. To get a circle, rounded shape or any custom outline, add an Image Mask/Blend filter and point it at a mask image. The mask image is a picture that decides which parts of the camera stay visible. To make the feed square or remove the edges, use the Crop/Pad filter. You can use both filters together. For example, you can crop the camera to a square first and then apply a circular mask.

"Shape" can mean two different things, and the answer depends on which one you mean. One is the outline of the visible camera area, such as a circle, a rounded rectangle or a hexagon. The other is the frame proportions, such as square instead of widescreen. A mask handles outlines. Cropping handles proportions.

Before you start

• Add your webcam to a scene as a Video Capture Device source, and confirm that a live image appears in the preview.
• Find out the camera resolution the source is using. You can see it in the source's properties. Your mask image should match this resolution or the cropped size.
• Have an image editor that can export PNG files. You will use it to make the mask.

If the preview stays black, OBS is not receiving video from the camera. Fix that first. The usual causes are another app using the camera, operating-system camera permissions, or the wrong device being selected. A mask cannot help until the camera image appears.

Step 1: Make a mask image

OBS does not include ready-made circle or shape masks, so you need to supply the image yourself. You can make one in two ways, and each way matches a different mask type in the filter:

• Color-channel mask: a black canvas with the shape drawn in white. White areas stay visible, black areas are hidden, and gray areas become partly transparent.
• Alpha-channel mask: a PNG with a transparent background and the shape drawn as a solid, opaque fill. Opaque areas stay visible and transparent areas are hidden.

OBS stretches the mask to fit the camera source. A perfect circle on a square canvas becomes an oval on a widescreen camera. To prevent this, make the mask canvas the same size as the camera image. Alternatively, crop the camera to a square first and use a square mask. If you want smooth edges, use your editor's anti-aliasing or a slight feather on the shape's edge.

Step 2: Crop the camera if you want a square or circle

• In the Sources list, right-click the webcam source and choose Filters.
• Under Effect Filters, click the plus button and add Crop/Pad.
• Enter crop values for the left and right sides so the remaining area is square. For a camera 1920 pixels wide and 1080 pixels tall, removing 420 pixels from each side leaves a 1080 by 1080 area.
• Check the preview to make sure your face is still centered. If it isn't, adjust the left and right values unevenly.

The figures in that example are simple arithmetic for that resolution. Calculate your own values from your camera's actual resolution.

Step 3: Apply the mask

• In the same Filters window, click the plus button under Effect Filters again and add Image Mask/Blend.
• Set Type to Alpha Mask (Color Channel) if your mask is white on black. Set it to Alpha Mask (Alpha Channel) if your mask is a transparent PNG.
• In the Path field, browse to your mask image.
• Leave Color at white and Opacity at full unless you want to tint or fade the camera.
• Close the Filters window and resize or move the camera source in the preview as usual.

Filter order matters. OBS applies Effect Filters from the top of the list to the bottom. Put Crop/Pad above Image Mask/Blend so the mask fits the cropped square rather than the full widescreen frame. To reorder filters, drag them or use the arrow buttons.

Optional: add a border or frame

The mask filter only hides parts of the image. It does not draw an outline. To add a ring or frame, create a PNG that contains only the border, with a transparent center. Add it as an Image source and place it above the webcam in the Sources list. Then align and resize it so it sits on the masked edge. To move the frame and camera together, select both sources and group them.

Rounded corners without making an image

Standard OBS has no built-in setting for rounding the corners of a source. You have two options. The first is to make a rounded-rectangle mask image and use the steps above. The second is to install a third-party plugin that adds shape or mask controls. No evidence was available here on specific plugins, how compatible they are with your OBS version, or how well they are maintained, so check those things before you install one.

Check the result

• The shape looks correct in the preview, with no stretching. If a circle looks oval, the mask and the camera or crop area have different proportions.
• The hidden areas show the scene behind the camera, such as your background image or game capture, and not a solid block.
• The edges look clean at the size you will actually display the camera. Jagged edges usually mean the mask has no anti-aliasing or is much smaller than the camera image.
• The mask stays aligned after you resize the source. If it shifts, check that cropping comes before the mask in the filter list.

Limitation when using the OBS Virtual Camera in calls

The OBS Virtual Camera sends the whole OBS canvas to a call app, and that output is always a rectangle. Areas outside the mask are not transparent there. They show whatever is behind the camera in your scene, which is black if nothing is behind it. To get a circular look in a call, place a background in the scene behind the masked camera. Also be aware that call apps may crop, mirror or apply their own effects to the incoming video. Do a test call to see how your shape appears to other people.

What this guide could not confirm

No tested results, version-specific screenshots or measurements were available. The menu names here describe OBS Studio's standard filters, but wording and layout can differ between versions and operating systems. If an option is named differently in your copy, look for it in the source's Filters window under Effect Filters.