April 21, 2025.
When one is viewing a file -- whether html, pdf, jpg, or whatever -- and whether or not in a browser -- one can "zoom in" by hitting <Command> + , or, if one has a keyboard that doesn't have a <Command> key, <CTR> + , one or more times, till one has gotten the size one wants. To "zoom out", one similarly uses <Command> − or <CTR> − .
I discovered this by accident; I'm curious whether it is well-known. If you read this and have the time, I would be interested to hear whether you were aware of it.
If you do this on an html file, the lines will re-format, rather than running off the tab. If you do this on a terminal (not in a browser), the terminal will expand or shrink. If expanding would make the bottom go off the screen, the number of lines will decrease accordingly (and remain decreased when one zooms back out, so one has to lengthen it by hand, if one wishes the original length).
When doing this zooming, one should be "in" the file in question. I.e., it is not enough just to move one's cursor into the image of the file: after doing so, one should click to be "in" the file.
When one has enlarged or shrunken a file, and leaves it and then goes back to it, one's view will in general still be enlarged or shrunken.