Can you hide a window from screen capture on Windows?
Yes, but only the app that owns the window can do it. The app calls SetWindowDisplayAffinity on its own window with the WDA_EXCLUDEFROMCAPTURE flag. From Windows 10 version 2004 onward, Windows keeps that window on your monitor and leaves it out of supported captures. It is an app feature, not a switch in Windows Settings.
Microsoft’s documentation puts it plainly: the window is shown on a monitor, and “Everywhere else, the window does not appear at all.” Its own example is recording controls that should stay out of the recording. OBS Studio, Signal and KeePassXC use the same flag; how screen capture exclusion works covers the API, those precedents and code samples.
Which Windows version do you need?
You need Windows 10 version 2004 (OS build 19041) or newer, or any version of Windows 11. There, an excluded window is absent from supported captures. On older Windows 10 builds, Windows treats the same request as an older mode, and the window appears in captures as a black rectangle with no content.
| Your Windows | What a capture shows | Why |
|---|---|---|
| Windows 11 | The window is left out | WDA_EXCLUDEFROMCAPTURE is supported |
| Windows 10, version 2004 or newer (build 19041+) | The window is left out | The flag was introduced in this release |
| Windows 10 before version 2004 | A black rectangle where the window sits | Falls back to the older WDA_MONITOR mode |
Kopya requires the same build, 19041 (64-bit), and warns you if it ever runs on something older.
How do you check your Windows version and build?
Press the Windows key + R, type winver and press Enter. The About Windows box shows a line such as Version 22H2 (OS Build 19045.xxxx). If the OS build is 19041 or higher, or the box says Windows 11, an excluded window is left out of captures rather than blacked out.
The number before the dot is the build; anything below 19041 is too old. Settings → System → About shows the same numbers.
Why does a hidden window show up as a black rectangle?
A black rectangle means the window is protected with the older WDA_MONITOR mode, which keeps the window on your monitor and shows it with no content everywhere else. You get it on Windows 10 builds before 19041 and in apps that choose it on purpose, as the sample in Microsoft’s Recall guidance does.
When you present, a blank box tells viewers something is there; an excluded window leaves nothing to look at.
Can you hide any window, or only an app’s own?
Only an app’s own. Microsoft documents three conditions: the window must be a top-level window, it must belong to the process that makes the call, and the Desktop Window Manager (DWM, see the glossary) must be composing the desktop. An app cannot use this API to exclude another program’s window.
If an app does not offer this, share a single window instead, or keep the window on a display you are not sharing. Five ways to hide a window from a screen share compares them.
What does capture exclusion not hide on Windows?
It keeps one window out of software capture, and nothing more. A phone camera, a person looking at your screen, a projector or mirrored display, the app’s tray icon and its process in Task Manager are all unaffected, as is monitoring software that inspects processes. Microsoft says the feature is not a security or DRM mechanism.
- Displays. A projector or mirrored display is a monitor, so people in the room see the panel even when people on the call do not.
- Other windows. The flag is set per window. A tray icon, its menu or a sign-in window stays capturable.
- The flag itself. Any process can read it with
GetWindowDisplayAffinity, as Microsoft documents.
How does Kopya use capture exclusion on Windows?
Kopya is a desktop AI assistant for macOS and Windows that answers questions about what is on your screen when you press a hotkey; its panel is excluded from supported screen shares and recordings. On Windows it does this through Electron’s setContentProtection, which Electron documents as using WDA_EXCLUDEFROMCAPTURE.
- On by default, on every plan, including the free plan with no card required (pricing).
- Three toggles: Ctrl+Shift+P, the panel’s privacy button, or the system-tray menu. The panel shows its state: “Hidden in screen shares” or “Visible in screen shares”.
- Only the panel is excluded. The tray icon, its menu and the sign-in window are ordinary windows.
- Capture only on your hotkey. Ctrl+Shift+Space takes one screenshot of the primary display. Kopya does not join calls or record audio.
- Not code-signed yet. Expect a SmartScreen prompt on first launch (download).
The screen-share privacy feature page covers both systems, but Windows is the stronger side. On macOS, Apple calls the equivalent flag a legacy constant, Electron documents that apps capturing through ScreenCaptureKit capture the window anyway, and built-in screen recording on recent macOS has been reported to show the panel. Read hiding an app from screen recording on Mac before you rely on it there.
How do you test it on your own PC?
Microsoft does not list which capture methods respect the flag, so check your own setup with the exact tool and share mode you plan to use, and look at what the other side actually sees.
- Make sure the panel says “Hidden in screen shares”. Ctrl+Shift+P toggles it.
- Start the exact tool and share mode you plan to use, or a recording.
- Join from a second device, or record ten seconds and play it back.
- If the panel appears, share a single window, move the panel to a display you are not sharing, or close it. Re-test after Windows or app updates.
The canonical checklist is the 60-second self-test. The compatibility page tracks what each vendor documents; the answers page and the other screen-share privacy guides cover the rest.
Common questions
Does it work in Zoom, Teams, Google Meet and OBS?
Kopya has not published test results for Zoom, Microsoft Teams, Google Meet or OBS Studio yet, and Microsoft’s documentation names no capture tools. OBS documents an option that hides its own windows with this flag. Run the 60-second self-test, then read the Zoom, Meet and Teams guide.
Does capture exclusion also cover screenshots and the Snipping Tool?
Microsoft lists no individual tools. Signal, which uses the same mechanism for its screen security setting, says nothing appears when you screenshot its window on Windows 11. Kopya has not published Snipping Tool results yet, so take a test screenshot.
Does it keep a window out of Windows Recall?
Microsoft’s Recall guidance tells app developers to use SetWindowDisplayAffinity to keep a window’s content out of Recall snapshots. Kopya has not published a Recall test for its panel yet; this page reports only what Microsoft documents for the API.
Is hiding a window from capture a hack?
No. SetWindowDisplayAffinity is a public, documented Windows API, and Microsoft’s own example is keeping recording controls out of a recording. What matters is where you use it: the responsible use page sets out what Kopya permits.
Sources
- Microsoft Learn — SetWindowDisplayAffinity
- Microsoft Learn — GetWindowDisplayAffinity
- Microsoft Learn — Recall guidance for app developers
- Electron docs — BrowserWindow (setContentProtection)
- OBS Studio PR #5698 — hide OBS windows from capture
- Signal blog — Screen security on Windows
- KeePassXC PR #6030 — screen capture protection