Your notes on screen.
Not on theirs.

You are thirty seconds into a product demo on Zoom. You have your talk track in Apple Notes, sitting in the corner of your screen. You share your screen to show the dashboard. And then your prospect says, “I can see your notes.”

It happens because of how screen sharing actually works on macOS. When you click “Share Screen” in Zoom, the application asks macOS for a continuous stream of pixel data — a live capture of everything visible on your display. Every window, every overlay, every floating panel. If a window is on your screen, it is in the capture buffer, and Zoom sends it to every participant.

This is not a Zoom bug. It is the expected behavior of the macOS screen capture framework, called ScreenCaptureKit (or the older CGWindowList API on pre-Ventura systems). Both APIs work by compositing all visible windows into a single image. Your notes app, your sticky notes, your text editor — they are all rendered into that composite. The distinction between “your stuff” and “stuff you are presenting” does not exist at the system level.

The workarounds people try

The most common fix is window-level sharing instead of full-screen sharing. Zoom, Teams, and Meet all let you share a specific application window rather than your entire display. In theory, this means only that window is captured. In practice, it is fragile. You have to remember to pick the right window every time. If you accidentally share your entire screen — which is the default in most apps — everything is visible. And if you need to switch between multiple apps during a demo (say, from your slides to a browser to a terminal), you end up sharing your whole screen anyway.

A second monitor helps, but introduces its own problems. Your camera captures you looking away from the lens. The eye movement is subtle on a single-monitor setup, but with a second display it becomes obvious — you are clearly reading something your audience cannot see. This is especially noticeable on Zoom, where participant video tiles are large enough to catch the lateral glance.

Your phone, propped up next to your webcam, has the same problem. The downward gaze is unmistakable. And scrolling through a phone while speaking is an obvious tell that breaks the natural flow of a conversation.

Slide presenter notes (Keynote’s “Presenter Display” or PowerPoint’s “Presenter View”) work only if your entire presentation lives inside one slide app. The moment you leave Keynote to show a live product, a browser, or a terminal, your notes vanish. And depending on how you share — screen vs. window vs. Keynote’s built-in sharing mode — the presenter view sometimes shows up in the share anyway.

Teleprompter apps like Notchie or PromptSmart solve a different problem. They scroll a linear script from top to bottom, optimized for reading a monologue verbatim. When you need to jump to a specific objection handler or pivot to a different topic mid-conversation, a scrolling script does not help. Conversations are non-linear. Your notes tool should be too.

The underlying issue with every workaround is the same: macOS treats every visible window as fair game for screen capture. Unless a window explicitly opts out of the capture buffer, it will be shared. No amount of window management or monitor arrangement changes this.

macOS provides a documented API for excluding individual windows from screen capture. It is the same mechanism that 1Password uses to hide your passwords from screen recordings, and that macOS itself uses for certain system-level UI elements. The API is sharingType = .none, set on the window’s NSWindow object, combined with content protection at the Core Graphics level.

When a window has its sharing type set to .none, macOS tells the window server — the system process that composites all windows into the image you see on screen — to exclude that window from any capture buffer. Zoom, Teams, Meet, Webex, Loom, QuickTime, OBS — any application that uses the standard macOS screen capture APIs will not receive pixel data from that window. It is as if the window does not exist for capture purposes, even though it is fully visible to you.

This is not a hack or an exploit. It is a first-party Apple API, documented in the AppKit framework reference, intended for exactly this use case: content that should be visible on the physical display but excluded from all forms of screen capture. Apple uses it in their own software.

The result is a notes window that is fully visible to you and completely absent from everything your audience sees. No split-second flash, no ghosting, no artifacts. The window is simply not in the data that leaves your Mac.