The 150ms benchmark in the title is really selling this short, the performance is very impressive. The 150ms seem to refer to the time it takes to initialize the graph, and with a hot cache that is more like 50ms for me here. Redrawing seems much, much faster.

I have done some visualization with WebGL because I couldn't get it fast enough with just drawing lines. That was a while ago so I'm not sure about the details, but even a simple prototype just drawing a few tens of thousands to a hundred thousand lines using canvas was slower than this for me (subjectively).

I'll have to look at the code later, but I'm curious about where this library is getting the performance from. Before I saw this I would have said you can't do this at this speed without using previously downsampled version of the data points, I'm not entirely sure now.

I'm still looking at the performance tab in the browser dev tools and how impressively empty the main Javascript usage plot is.