Normally Google uses Arial, which also is Firefox's default "sans-serif" font on Windows. So usually it's pretty reliable. Could you check something: what font is Firefox trying to use for the text that shows as boxes? To check that, right-click some of that text and choose Inspect Element. This should open Firefox's Page Inspector in the lower part of the tab. The left has has an HTML "tree" of the document and on the right side, there are several different panels. The one to check is called Fonts. If you cannot see a little Fonts heading, try clicking the triangle on the right side to show the hidden panels. Here's an example: <img src="https://prod-cdn.sumo.mozilla.net/uploads/images/2018-04-03-22-33-49-bd055a.png" width="500"> What Font is Firefox using for the problem text?