Thy wish is my command, sire....
Go to the Settings page and type zoom. Look at the second hit.
BTW, regarding Windows, you may be able to get what you need with a pixels per inch display settings change rather than magnification. Or even in system fonts.
Hey now; none of that sire stuff;
I'm just a servant of the most high God>Jesus;
like yourself. And a not too bright a one sometimes; but I keep learning; even if it's things that I used to think I knew; like the difference in DPI and PPI.
Used to think I knew and understood how screen resolution, dots per inch, pixels per inch, and zooming all interrelated; but after your saying changing PPI would do the same as zooming; I had to go do some studying online.
People use DPI and PPI inter-changeably for the number pixels in a LCD but DPI is mainly used for printers. A LCD's number of pixels per inch is a physical measurement and can't be changed. So when we change the PPI; we are actually changing the magnification.
So I looked up and found, in display advanced settings; that Win10 (don't know if W8-8.1 is the same) has; in addition to the resolution (which in my case is 1600x900) a setting for, from 100% to 150% to change the size of "texts, apps and other items" so set this for 150 like I would with zoom in SJ. Well it worked, but not only were the web pages enlarged; but also my icons on the desktop and the address bar, bookmarks bar and tabs. Which, for the icons, threw them out of alignment and kind of jumbled them together. Well that wouldn't work; so went back to display settings and tried to set the scroll control back to 100%; but it wouldn't go, kept bouncing back to 150; so found another control in advance, that had a ruler and another control, which was called "scaling" and set it to 100.
Well the icons went back to medium; and, low and behold; the task bar, start menu and all lower icons were gone again. Well... I wasn't even surprised any more; after all the crashes and problems I have gone thru with this PC, the last 4 months or so; so I restarted, crossed my fingers and luckily everything came back. So I left the pexied display settings alone and went and tried the settings in Slimjet; altho I didn't expect it to work, as I had changed the zoom setting in the menu pull-down before and had seen the other one in settings; it was on 100 like the menu one; so set it to 150% and tried a few web pages and it worked! I guess the one in the menu is for an individual page and the one in settings is permanent; I SURE hope so. Thanks again Paul.