What is screen capture exclusion?

How does screen capture exclusion work on Windows?

Windows draws the desktop through the Desktop Window Manager (DWM), which combines every window into the image on your monitor. Capture tools ask Windows for a copy of that image. When a window has the exclusion flag, DWM still draws it on the monitor but skips it when building the copy that capture tools receive. Viewers see whatever was behind the window.

The function is SetWindowDisplayAffinity in user32.dll. According to Microsoft's documentation, it accepts three values:

Two rules from the docs matter. Only the process that owns a top-level window can set its affinity, so you can't apply it to someone else's app from the outside. And on Windows versions before 10 version 2004, asking for WDA_EXCLUDEFROMCAPTURE behaves like WDA_MONITOR, which means a black box instead of an invisible window. Press Win + R and run winver to check your version.

Which apps respect it?

Anything that captures the screen through Windows' own capture paths: Windows.Graphics.Capture, DXGI Desktop Duplication and GDI BitBlt. In practice that covers the Zoom and Microsoft Teams desktop apps, Google Meet in Chrome or Edge, Slack and Discord screen sharing, OBS, Loom, the Xbox Game Bar recorder, the Snipping Tool and PrintScreen. Microsoft's own example use is video recording controls that shouldn't end up in the recording.

What are the limits of screen capture exclusion?

Microsoft is direct about this: unlike DRM or a security feature, there's no guarantee the content is protected, and a photo of the screen is the obvious example. Specifically:

• Cameras. A phone or webcam pointed at the monitor sees the window.
• Hardware capture. Capture cards, projectors and duplicated displays receive the monitor signal, which includes the window.
• Remote desktop. Some remote-desktop and remote-support tools work outside the normal capture APIs; test yours.
• Old Windows. Before version 2004 you get a black rectangle, which viewers notice.

So the accurate claim for any app using it is "excluded from screen capture by Windows". Not "undetectable", and not "impossible to see". Tools that promise more than that are promising something the API doesn't do.

How do other platforms and frameworks handle it?

Electron apps call win.setContentProtection(true). The Electron docs say this calls SetWindowDisplayAffinity with WDA_EXCLUDEFROMCAPTURE on Windows, and on macOS sets the window's sharingType to NSWindowSharingNone. Native WPF, WinUI and Win32 apps call the function directly with the window handle. Our deep dive, WDA_EXCLUDEFROMCAPTURE explained, has C# and C++ code and a test matrix.

What is it used for?

Recording controls and capture tools hide their own buttons from the output. Password managers and banking apps can keep sensitive windows out of screenshots. And private overlays keep notes or AI answers on the presenter's screen while the audience sees the shared content without them. If you just want to keep one app private during a call and don't need an overlay, sharing a single window instead of the whole screen is simpler; our guide to hiding a window from screen share compares four methods.

Screen capture exclusion in AuraCloak

AuraCloak, an AI overlay for Windows, calls SetWindowDisplayAffinity(hwnd, WDA_EXCLUDEFROMCAPTURE) on its window, and file pickers opened from the overlay are hidden too. On Windows builds before 2004 it falls back to WDA_MONITOR, so the window shows as a black box. You can turn exclusion off in Settings or with [Privacy] ExcludeFromCapture=false in auracloak.ini, which is handy when you want to record a tutorial of the app itself.

FAQ

What does WDA_EXCLUDEFROMCAPTURE do?

It's a value for the Windows function SetWindowDisplayAffinity that keeps a window visible on the monitor but removes it from screen capture. Screenshots, recordings and screen shares that go through Windows show what's behind the window instead. It requires Windows 10 version 2004 or later.

Can Zoom or Teams see a window with screen capture exclusion?

Not in the shared screen. The Zoom and Teams desktop apps capture through Windows capture APIs, which skip excluded windows on Windows 10 version 2004 and later. People on the call see whatever is behind the window. A camera pointed at your monitor would still show it.

Why does an excluded window show as a black box?

On Windows versions before 10 version 2004, WDA_EXCLUDEFROMCAPTURE isn't supported and Windows treats it like WDA_MONITOR, which blanks the window's content in captures instead of removing it. Updating Windows fixes it. Run winver to check your version.

Can I hide any app from screen capture this way?

No. Only the app that owns a window can set its display affinity, so you can't apply it to another program from outside. To keep a regular app private, share a single window instead of your whole screen, or move the app to a monitor you aren't sharing.