Press Alt + PrtScn to capture the active window on Windows
Press Windows + Shift + S and select the window area to capture on Windows
Use Snipping Tool or Snip & Sketch and choose Window Snip
On Mac, press Command + Shift + 4, then press Spacebar and click the window
On Mac, use Command + Shift + 5 and choose the window capture option
On Linux, use the Screenshot tool and select the window option
On Chromebook, press Ctrl + Show windows and choose Window capture if available