Why does MathJax render differently on different devices?

On my laptop (macOS), $$\mathbin{\rlap{\,\,\bullet}\triangle}$$ renders as

On my phone (Android), however, the same code (i.e. $$\mathbin{\rlap{\,\,\bullet}\triangle}$$) renders as

(Note that the size difference is because of the difference in image size, not because of MathJax.)

Why does MathJax render differently on different devices? Is this a MathJax bug, an SE bug or a local bug, and is there a way to fix it?

You can check what it looks like here in this post for you: $$\mathbin{\rlap{\,\,\bullet}\triangle}$$

Edit: It seems that the rendering is different on my laptop and phone only when using the HTML-CSS renderer.

• I have included the MathJax formula directly in this post - so that others can see how this displays to them. I hope that's ok. (I have tried various MathJax rendererers on the same device - but I did not notice a substantial difference between the renderers. only Preview HTML looks rather different from the other ones.) Jul 13 at 8:07
• On your phone, which is likely an iphone, the XITS fonts are installed and this is the default (common HTML renderer). You can change the behavior as in the above post Jul 13 at 8:09
• @MartinSleziak Sure. Calvin, what is strange is that both my phone and laptop use the HTML-CSS renderer, but still produce different outputs. Also, I'm on an Android.
– user1082389
Jul 13 at 8:15
• Well...that's news to me then! In any case, the output is virtually identical to your phone on my mac, and also on my iphone, when using the common HTML renderer. Jul 13 at 8:31
• What happens if you change the renderer on your phone? IIRC It is supposed to specifically not use XITS in one of them Jul 13 at 9:25
• @CalvinKhor It seems that the output on my phone and laptop are virtually identical on every renderer except the HTML-CSS renderer.
– user1082389
Jul 13 at 9:36
• My first comment had a typo because I misremembered. On Macs/iOS devices, the HTML-CSS renderer uses the XITS font. Jul 14 at 2:17
• @CalvinKhor That pretty much solves it, I guess.
– user1082389
Jul 14 at 5:38