16GB will make a noticeable difference for your 2012 Mac Mini.

Yes, it’s worth doing if you’re feeling the memory pressure. Modern web browsers are memory hogs—a handful of tabs plus a few extensions easily chews through 8GB. Light video editing (1080p in iMovie, basic cuts in DaVinci Resolve) will also benefit because the OS won’t have to constantly swap to disk.

8GB DDR3-1600 was fine in 2012, but today’s web pages and editing software are heavier. The CPU (Ivy Bridge i5 or i7) is still decent for basic tasks, but RAM is the bottleneck. You’ll notice it in smoother tab switching, less freezing when loading large sites, and fewer pauses while editing.

The upgrade is cheap—used 16GB kits (2x8GB) run around $20-30. Just make sure your mini supports it (the 2012 models do, up to 16GB officially, though some have run 32GB unofficially