3Blue1Brown
3blue1brown.com
Grant Sanderson's maths lessons, with the visuals inline
Explain Everything
A hub for every explainer you can play with
explorabl.es
Rabbit hole · Works anywhere
Free, no sign-up · online since 2015
Nicky Case's index of interactive learning pieces, sorted by subject and gathered from across the web. Entries cover social systems, biology, maths, art and civics, and a separate section explains how to build your own explorable if you catch the bug.
It is the best jumping-off point in the entire genre, because every link has been checked by somebody who makes these things himself.
Keep going
Picked for a shared category and overlapping vibe, not for popularity.
3blue1brown.com
Grant Sanderson's maths lessons, with the visuals inline
pomax.github.io
Everything about the curve behind every vector graphic
ciechanow.ski
The best interactive explainers anyone is making
complexity-explorables.org
Play with the models behind epidemics, flocks and chaos
cpu.land
What happens between typing a command and seeing output
distill.pub
Machine learning papers you can actually see working