For Windows · Free & open

Lock what others shouldn't see.
Unlock what matters.

ScreenBlind selectively locks the monitors you choose — the others stay visible and keep displaying their content, so a presentation, video, or dashboard can carry on while you step away from your desk. Mouse and keyboard input stays captured by the lock.

Windows 10 & 11 · ~40 MB · No installer required · v1.0.0

Built for multi-monitor setups

A focused privacy tool that does one thing well.

🖥️

Selective locking

Choose which monitors to lock. The unlocked screens keep displaying their content — perfect for leaving a presentation running, a video playing, or a livestream visible while you step away.

🔒

Password-protected

Set a single password. It's hashed with PBKDF2-SHA256 and stored only on your machine. Wrong password? Helpful shake-feedback.

Built-in screensavers

Bubbles, Matrix rain, or your own image slideshow take over after the idle timeout — with shifting dark hues so the lock screen never looks dead.

🧠

Smart input handling

Mouse cursor stays trapped inside locked screens, can't escape to your unlocked monitor. The Windows key is blocked from opening Start.

🎨

Roaming clock

Clock and date drift to random positions on the screen at intervals — keeps the lock screen alive and avoids burn-in worry.

🪶

Lightweight

Single executable, no installer, no background services, no telemetry. Lives quietly in your system tray until you need it.

See it in action

Pick your screens in a small tray app — the locked ones go dark while the others keep working.

ScreenBlind main window — Monitors tab listing four detected displays with checkboxes
Open ScreenBlind, tick the displays you want covered, and press Lock Now. The unticked screens keep running normally.
Before Four monitors visible before locking — desktop, OBS with ScreenBlind dialog, and two wallpapers
Four-monitor setup, ScreenBlind dialog open on screen 2.
After Same setup after locking — leftmost two screens show a clock lock overlay, the other two keep showing their content
Screens 1 and 2 are locked with a roaming clock — screens 3 and 4 keep displaying as before.

How it works

Three clicks from open to locked.

  1. 1

    Pick the screens to lock

    The Monitors tab lists every connected display. Check the ones you want covered — typically your laptop screen and the side monitor, leaving the center one to keep showing whatever's on it.

  2. 2

    Set a password

    One time only, in the Security tab. Your password is hashed locally — ScreenBlind never sees it in plaintext and nothing leaves your computer.

  3. 3

    Hit "Lock Now"

    Selected screens turn into a quiet, animated lock surface. Move the mouse or press a key on a locked screen to bring up the password prompt. Unlock once — every screen comes back.

Honest about its limits

ScreenBlind is a focus/privacy tool — it isn't a replacement for the Windows lock screen. Here's what it can and can't do.

⚠️

Win+L still works

The Win+L shortcut is processed by the Windows kernel before any user-mode application can intercept it. No regular app — not even with administrator rights on Windows 11 Home — can reliably block it.

What happens if pressed: the Windows lock screen appears. After entering your Windows password, ScreenBlind's overlay is still active underneath and will require its own password.

⚠️

Ctrl+Alt+Del still works

Ctrl+Alt+Del is a hardware-level Secure Attention Sequence built into Windows specifically so that no software can ever intercept it. This is a feature, not a bug — and it's true for every third-party lock tool.

What happens if pressed: same as Win+L — the Windows security screen appears. ScreenBlind comes back after dismissal.

🛡️

Effective security model

Even though those two shortcuts can't be blocked, they don't really weaken security: anyone who triggers them now has to enter both the Windows password and your ScreenBlind password to see the locked screens. That's stronger than either alone.

🖥️

Windows-only, for now

ScreenBlind is built on top of Windows-specific APIs (cursor clipping, top-most window enforcement, keyboard hooks). macOS and Linux ports are on the wish list but not currently available.

Get ScreenBlind v1.0.0

Download the latest build for Windows 10 and 11. One file (~40 MB), no installer, no service.

⚖️

Use at your own risk

ScreenBlind is provided "as is", without warranty of any kind, express or implied. By downloading and running this software, you accept full responsibility for any consequences, including but not limited to data loss, lost productivity, hardware misbehavior, or being unable to access a locked screen due to a forgotten password.

The authors and contributors are not liable for any direct, indirect, incidental, or consequential damages arising from the use of this software. ScreenBlind is a privacy / focus utility — it is not a substitute for full disk encryption, the Windows lock screen, or enterprise endpoint protection. Always have a recovery plan in place (a written-down password, access to another admin account, etc.) before relying on it.