If you've searched for screen privacy tools, you've probably seen two categories: tools that blur parts of your screen, and tools that exclude windows from capture entirely. They solve different problems, target different users, and fail in different ways.
Here's how to tell which approach you actually need.
Category 1: Blur and Overlay Tools
These tools draw a visual mask — blur, pixelation, or a solid color — over sensitive areas of your screen. The underlying content is still in the capture stream; it's just visually obscured.
ContextBlur
A browser extension + system tray utility that lets you blur specific page elements, form fields, or desktop regions. Good for web demos where you need to show a dashboard but hide customer names or revenue numbers.
Best for: Web-based content, quick demos, browser-specific masking.
Limitation: The blur is a visual overlay, not a capture exclusion. A determined recorder or screenshot tool can sometimes capture the unblurred layer beneath. And it doesn't help with native apps like Slack or your password manager.
DataBlur
A browser extension focused on automatic PII detection and masking. It identifies emails, phone numbers, and account numbers and blurs them without manual selection.
Best for: Browser-based screen shares where PII appears unpredictably.
Limitation: Browser-only. No protection for desktop apps, notifications, or taskbar metadata.
ScreenBlur
A Windows Store app that locks your screen behind a custom blur or opaque overlay when you step away. More of a physical privacy screen than a screen-sharing tool.
Best for: Office environments, shoulder-surfing protection.
Limitation: Not designed for live screen sharing. The overlay covers everything, including what you want to show.
Category 2: Capture Exclusion (Cloaking)
These tools use OS-level APIs — SetWindowDisplayAffinity on Windows — to remove specific windows from the capture stream entirely. The window is visible to you. It simply doesn't exist in the frame buffer that Zoom, Teams, OBS, or Snipping Tool receives.
Evanesco
GitHub: k4yt3x/Evanesco
Free, open-source, basic GUI. Hide a window from capture.
CaptureGuard
GitHub: xzulab/CaptureGuard
Newer, Rust-based, single EXE. Clean process picker.
WinHider
GitHub: aamitn/winhider
Free, Microsoft Store, also hides from taskbar/Alt-Tab.
NoCapture
The only tool in this category that adds metadata protection: title masking, notification shielding, live preview, and workflow routines.
When to Blur vs. When to Cloak
Use Blur
-
Demoing a web dashboard with customer data
- ContextBlur
- DataBlur
-
Physical shoulder-surfing protection
- ScreenBlur
Use Cloak
-
Hiding Slack, Discord, or email from a live stream
- NoCapture
- Evanesco
- CaptureGuard
-
Preventing tab titles from leaking
- NoCapture title masking
-
Blocking notification popups
- NoCapture notification shield
Quick Rule
- Blur when you want to obscure what's visible on your screen.
- Cloak when you want to prevent content from being captured or exposed.
The Hybrid Approach
NoCapture can handle all of these use cases on its own. Whether you're demoing a web dashboard, sharing a native app, or protecting sensitive content from entering the capture stream, NoCapture provides comprehensive screen-share privacy without needing separate blur and cloaking tools.
We wrote about the three layers of screen-share privacy here. While traditional blur tools only address layer one (pixels) for specific regions, NoCapture addresses all three layers — pixels, metadata, and workflow — across entire applications.
The Honest Limitation
Neither approach stops a camera pointed at your monitor. Neither stops kernel-level capture bypasses. Microsoft documents this explicitly: WDA_EXCLUDEFROMCAPTURE is not a security boundary.
What both approaches do is eliminate the accidental leak — the notification, the background window, the unmasked field — which is where real damage happens.
NoCapture provides OS-level window cloaking, title masking, and notification shielding for Windows. Free for two windows. Because "being careful" isn't a strategy.
