# Consider changes to the font used for MathJax and bolded text

As the following image shows the font size of mathematical text and bolded text are larger than the ordinary text, at least in my browser (Chrome v47 on Mac osX):

The image is snapped from this answer. Could you please look into whether this is something which might be corrected, and/or is a problem for multiple people on different operating systems and different browsers.

Added: Image from Win8 and Chrome (provided by Quill), the bold text is a little better, but the MathJax is still too big:

Added: Firefox 42.0 on Windows 7:

Added Internet Explorer 11, Windows 7:

Could you please look into whether this is something which might be corrected

The bold, is a problem with the font. There is no CSS change that makes the text larger. And if you change the font-weight to normal, it's exactly the same as the text around it. The only fix I know for this would be to use a new typeface.

However the MathJax is potentially due to a configuration that changes the font size by ~124%. This in my opinion is too big. If we look at Math.SE their inline MathJax has a font increase by ~111%. And to me looks the same size as the font surrounding it. (maybe a tad larger)
I think asking for the size to be reduced is fixable and reasonable.

is a problem for multiple people on different operating systems and different browsers.

The MathJax is definitely OS and browser independent. If you are using a browser with a GUI and a JavaScript engine the MathJax should always be larger. As, as far as I can tell, JavaScript is dynamically adding font-size: 124% to the MathJax elements.

The bold font is probably OS, browser and font dependent, as it's how the system handles displaying the font. But the bold font seems to have the same height as the rest of the text and is only thicker, in all the screen shots. And so the bold is probably more a personal dislike of the font in it's font family.

I think the MathJax typeface should be kept the same, however the font-size should be reduced to something more reasonable.

We may get a new typeface that may 'fix the bold issue' if the developers agree with Use a font family which has an actual italic variant (instead of oblique). But I think the bold font is fine. It fulfills it's task well, maybe too well.
One way you could fix this is to use italics for emphasis. And bold to draw attention. (Which is how they are ment to be use, IIRC)

In my experience, such results are very dependent on the zoom level and font size. For example, if I zoom the linked question one level, then the two fonts are the same size for me. That suggest that this is a font rendering issue, not a configuration problem. Rasterizing an outline font is a tricky business, and it has all kinds of pitfalls related to rounding to the nearest pixel. My suspicion is that the ex-height does not match the pixel grid very well, and that for the bold case, there is something being rounded up and in the non-bold case, it is being rounded down, and that causes the one pixel difference that you are seeing. When the characters are only 8 pixels tall, as in your first example, a one pixel difference is pretty significant.

As for the MathJax output, MathJax tries to match its font size to the size of the surrounding text using the ex-height. Unfortunately, it has to determine that ex-heigh empirically using whole pixels, and in the case where the ex-height doesn't match the pixel grid very well, the estimate of the ex-height can be off, and it can end up over- or under-scaling its fonts. That appears to the be the case here. For example, try zooming out one level and reloading the page. For me, MathJax gets the size better in that case.

So these things are very dependent on the font size, and the zoom level can make a difference to that.

Note, however, that MathJax has a Contextual Menu where you can provide a global scaling factor. (Right click or control click on a typeset equation to get the menu, then choose Math Settings and Scale All Math... to change the value to suit your situation.) That can be used to make the math match better. For the bold, you would need to use a Greasemonkey script or its equivalent to adjust the size of the bold font. I doubt it is worth it, though.

• I find it unfortunate that it looks like this with default settings, and would have loved for it to be better by default – holroy Dec 9 '15 at 15:58
• I agree, but that would probably take either a change in the default font, or a change in the default font size. I haven't tried adjusting the size, but it might be that using 16px rather than 15px (the current size) might be enough to make it fit the grid better. – Davide Cervone Dec 9 '15 at 17:14