basically I'm looking to press a single keyboard shortcut, similar to Cmd+Shift+4, except rather than having to draw my own box, I'd like a box of a predefined dimension appear, such as 300px x 300px that I can move around.

Or an alternative would be to have Cmd+Shift+4 work at a fixed aspect ratio, for example hold down alt and it will be locked to 1:1

The only tool I've found to do this is Snapz X Pro but the price is a bit crazy when I only need it for make screen snips.

My job has a task that requires making multiple (dozens or hundreds) of 1:1 screenshots of various things, I can't fiddle with the mouse down to the pixel. I also can't deal with going through 3 menus and saving and typing my own file name either, but that wouldn't be the end of the world.

If I could just lock the aspect ratio with Cmd+Shift+4 I could start large and batch resize the snips when I'm done, that would be a good alternative.

  • 2
    I do agree that its price does seem high, but since you say that My job has a task that requires making multiple (dozens or hundreds) of 1:1 screenshots, wouldn't purchasing Snapz Pro X be a work expense? Anyway, the answers in the possible duplicate @Allan refers to should meet your needs.
    – Monomeeth
    Jun 2, 2017 at 23:56

1 Answer 1


You can use the screencapture tool, part of macOS:

screencapture -x -Rx,y,w,h /path/to/capture.png

x,y is the coordinates of the top-left point of the rectangle,
w,h is the dimensions of the rectangle,
-x mutes the capture.

You could wrap this in an Automator workflow or Keyboard Maestro macro and customise it to your desired output.

  • +1 You could even make it a service & then key-command it similar to the regular ScreenCapture - I wrote an answer on turning an Automator action into a Service [for different purposes but the workflow is there] - apple.stackexchange.com/a/258741/85275
    – Tetsujin
    Jun 3, 2017 at 7:34
  • Thanks but the coordinates change, I need to be able to move it around.
    – screampuff
    Jun 4, 2017 at 0:42

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