How to increase font size on iMac?

[CloudWatcher]

9. Application specific

Note that cmd+ and cmd- are specific to the application you're using (Safari or Textedit or whatever). And not all applications support cmd+ and cmd- to change font size.

Changing the screen resolution (using the "Displays" panel in System Preferences) can make each "pixel" on the screen bigger (or smaller), so everything appears bigger or smaller by default -- across all your applications.

And in case you want to explore a little more:

If you have poor vision, there is a wonderful (and almost unknown) feature in macOS where you can temporarily "zoom into" the screen and magnify what you're looking at. I use it all the time, but it is not enabled by default.

If you are interested, the steps are (sorry, it is more than one step to enable it, but then it's easy to use):

1) launch the System Preferences application (you can find in in the Applications folders with all the other applications, or use the shortcut under the Apple menu in the top-left).
2) find the "Accessibility" panel (use the View menu and find Accessibility or click on it in the list of panels).
3) find the "Zoom" entry in the left section of the Accessibility panel
4) click "Use scroll gesture with modifier keys to zoom"

This will enable "zoom" mode where you can hold down the control key while scrolling to zoom into (and back out) of the screen to temporarily make something more readable.

The settings in Zoom allow for a lot of different styles of zooming and different key-combinations to invoke it.

Anyway, this zooming works with anything on the Mac screen. It doesn't need support from each application. It takes a little getting used to, but I find it to be very very useful!