Dark Mode

that would be a good idea

There are many existing discussions here in the Support Community about dark mode.  (In general, it's often better to add your comments to an existing discussion about the topic rather than create yet another separate discussion on the same topic.)

In one Dark Mode discussion, KA Support Advocate Evan Lewis posted in May 2025 that adding dark mode to KA would require lots of resources and 'it’s unlikely that a native dark mode will be available in the foreseeable future.'  KA suggests the free open-source Dark Reader browser extension; 'it does not collect any user data. I’ve tested this extension myself and found that it works reasonably well on Khan Academy, especially when using the "Dynamic" theme generation mode.'

Good luck.
~ Janice, KA user