Focus Border is a small background app for X11 desktops. It polls the active window and draws a transparent, click-through border around it so the focused window is easier to spot.

• python3
• PyGObject with GTK 3
• xprop
• xwininfo

python3 focus_border.py

Useful flags:

• --color ff5f57
• --alpha 0.95
• --thickness 4
• --radius 10
• --inset 6
• --poll-ms 120

Example:

python3 focus_border.py --color 00b894 --thickness 6 --radius 14

Install the desktop entry into your autostart folder:

python3 focus_border.py --install-autostart

That copies io.github.sander.FocusBorder.desktop into ~/.config/autostart/.

• This targets X11. It will not work on native Wayland-only sessions.
• Fullscreen windows are ignored so the overlay does not sit on top of full-screen apps or videos.
• The desktop entry currently points at this checkout: focus_border.py