Dark mode makes page very laggy

Windows 11, Firefox 111.0.1 (64-bit)

When I switch to dark mode everything on the simbrief site becomes much slower. Scrolling, expanding sections, opening drop-downs etc.

Switching back to light mode immediately fixes it.

Video showing the difference: Laggy dark mode - YouTube

Hi, thanks for the report!

May I ask what your computer hardware is? Specifically what processor, memory, and graphics card (if any) do you have?


I forgot to mention them because they definitely shouldn’t be an issue:

i7 12700k
64 GB ddr4 3600 MHz
Titan RTX

Agreed, shouldn’t be an issue!

But even the light mode is a bit laggier than I’d expect when panning around the map.

Can you try in a different browser (Edge or Chrome)? Just want to see if it’s limited to Firefox or not.


Yes, it does seem to be Firefox-specific. Edge is smoother in both light and dark mode. There’s still a difference between light and dark, but not nearly as pronounced.

Can you try changing this setting and see if it makes a difference? In other words, uncheck “Use recommended performance settings” and either tick or untick the “Use hardware acceleration when available” box.

Make sure to restart Firefox after changing this setting as well.


It turns out hardware acceleration was unchecked. When I saw that screen I had a bit of deja vu. I think there was some site I was having trouble with a year or two ago and disabling hardware acceleration fixed it. No idea what it was, but turning it back on resolved the simbrief issue.

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