How to Chroma Key in Photopea: Step-by-Step

Chroma keying (often called green screen) is a technique where you remove a uniform background color from an image, usually green or blue, and then place the subject onto a new background. Photopea is a free, browser-based photo editor that includes a powerful tool for this task. This guide shows you how to do it step by step, from opening your image to exporting the final cutout.

What You’ll Need

A photo with a solid green or blue background (the more even the color, the better).
A web browser (Chrome, Firefox, Edge, etc.) with internet access.
A replacement background image (optional but recommended).

Step-by-Step

Open Photopea and your image. Go to photopea.com. Click File > Open and select your green screen photo. Alternatively, drag and drop the image file directly into the browser window.
Select the Magic Wand tool. In the toolbar on the left, find the Magic Wand (it looks like a wand with a sparkle). If you don’t see it, click and hold the Lasso tool to reveal it in the dropdown.
Set the tolerance. In the top options bar, set the Tolerance to around 20–30. This controls how similar a color must be to the one you click to be selected. Start with 25.
Click on the background. Click once on the green or blue background area. A selection (marching ants) should appear around the background. If it selects too much or too little, adjust the tolerance and try again.
Refine the selection (optional). If the selection missed some areas, hold Shift and click on those areas to add them. If it selected parts of your subject, hold Alt and click on those areas to subtract them.
Invert the selection. With the background selected, go to Select > Inverse (or press Ctrl+Shift+I on Windows / Cmd+Shift+I on Mac). This selects your subject instead of the background.
Add a layer mask. At the bottom of the Layers panel, click the “Add layer mask” icon (a rectangle with a circle inside). This hides the background and makes your subject transparent. You should see a checkerboard pattern behind your subject.
Add your new background. Click File > Open & Place to insert your replacement background image. Drag that layer below your subject layer in the Layers panel. Your subject now appears on top of the new background.

Common Mistakes

Using a background that is not evenly lit. Shadows or bright spots on the green screen make it harder to select just the background.
Setting the tolerance too high. This can select parts of your subject that have similar colors, like green eyes or blue jeans.
Forgetting to invert the selection. If you delete or mask without inverting, you’ll remove your subject instead of the background.
Leaving a green fringe. After masking, a thin green edge often remains around the subject. See Tips below on how to fix it.

Tips

Use a high-contrast background. Green works best for most subjects, but if your subject has green clothing, use a blue screen instead.
Feather the mask slightly. In the Layers panel, right-click the mask and choose Feather (or go to Select > Modify > Feather before creating the mask) with a radius of 1–2 pixels to soften edges.
Remove green fringe. After masking, click on the mask thumbnail, then go to Image > Adjustments > Desaturate to remove color cast, or use Layer > Matting > Defringe to clean up edges.
Use the Brush tool to fix mask edges. Select the mask, then use a black or white brush to paint out or restore areas.

Troubleshooting

The selection includes parts of the subject. Lower the tolerance and try again. You can also use the Lasso tool to manually subtract areas from the selection.
The background is not fully selected. Increase the tolerance, or click multiple times while holding Shift to add more areas.
The subject has a green or blue tint. After masking, go to Layer > Matting > Remove White Matte or Remove Black Matte depending on your background. Or use Hue/Saturation to reduce the green/blue saturation.
The mask is too harsh. Use the Blur filter on the mask (select the mask, then Filter > Blur > Gaussian Blur with a small radius) to soften edges.
Can’t see the checkerboard. Make sure the mask is applied correctly and that the layer is not hidden. Also, check that the background layer is below the subject layer.

Frequently Asked Questions

Do I need to download Photopea?

No, Photopea runs entirely in your browser. You don’t need to install anything.

Can I use a blue screen instead of green?

Yes. The same steps work for any solid color background. Just click on the blue area instead of green.

How do I save the image with transparency?

Go to File > Export As > PNG. PNG supports transparency, unlike JPEG.

Can I chroma key a video in Photopea?

Photopea is primarily for still images. For video, you’d need a video editor like OpenShot or DaVinci Resolve.

Why is there a green outline around my subject?

That’s called a color fringe. Use the Defringe matting option or desaturate the mask edges as described in Tips.

Is Photopea really free?

Yes, Photopea is free to use in the browser. There are optional paid features, but the chroma key tools are available for free.

Sources: general know-how. Menus and buttons can differ slightly by version. Spotted something out of date? Tell us.