Mac windows move when the monitor turns off.

Your Mac does not have to sleep for this to happen. When you switch an external monitor off, or it drops into power saving after a few minutes, many monitors cut the connection completely. macOS treats that as the display being unplugged and moves its windows onto whatever screen is left. When the monitor comes back, the windows usually stay where macOS put them.

What free fixes should you try first?

• Let macOS sleep the display. Use the Lock Screen or display sleep settings instead of the monitor power button. Many monitors stay connected in that state.
• Turn off deep sleep in the monitor. Settings called deep sleep, eco, auto power off or power saving often drop the connection. Dell, LG and Samsung menus all have a version of this.
• Turn off auto input detection. A monitor that scans inputs when idle can briefly disappear from the Mac.
• Try DisplayPort or USB-C. HDMI connections are more likely to drop fully when the monitor is off, depending on the model.
• Keep one display on. With a laptop open, its built-in screen stays connected, so at least the windows have somewhere predictable to go.

Your layout back after the monitor comes on. The 40 second demo shows a workspace saved from the SnapState menu bar and restored with one click: apps relaunch and windows go back to their saved displays, positions and sizes.

Why is this different from sleep?

With sleep, the whole Mac goes quiet and every display reconnects on wake. Here only one monitor disappears while the Mac keeps running, so macOS rearranges windows right away. If your issue happens on wake instead, see why Mac windows move after sleep, windows move when switching monitor input and windows move after the lock screen.

How does SnapState put the windows back?

SnapState is a Mac menu bar app that saves a named workspace: every window with its display, position and size, the apps to relaunch, the Space each app was on, full screen windows, and all open tabs in Safari, Chrome, Edge, Brave, Arc and Chromium. Restore it from the menu bar, with a Control-Command-1 to 6 shortcut, or automatically when a monitor connects or disconnects, on wake, or when a matching display layout appears.

Arm the monitor connect trigger and turn the display back on. SnapState sees the monitor return and puts each window back on it. It cannot stop the monitor from disconnecting, and it does not move the menu bar or Dock.

What are the practical details?

SnapState 2.7.5 costs $9.99 once, with a license for up to three Macs and a 14-day refund. It needs macOS 15.7 or later and runs natively on Apple Silicon and Intel. It needs Accessibility permission to move windows, and Automation permission if you want browser tabs reopened. Workspace data stays on your Mac. See SnapState.

What are the honest limits?

SnapState is not a tiling or snapping tool. It does not save browser tab groups, history or form data, Firefox is not supported, and it does not change the display arrangement, main display, menu bar or Dock. It restores app windows.

Frequently asked questions