Thanks for checking it out! I am wondering how big is the number you are putting in? If the number is really high, it's probably causing a stack overflow. I would limit the size, but each browser has its own recursion limits so that would be quite a pain. In retrospect, I probably should not have used a recursive algorithm for this task :).

I put in a value of 500, and while it didn't freeze completely, it really struggled to respond.

Recursive division may be elegant, but it seems that may also have its disadvantages.

One trick you could use is to add a setTimeout or asnyc/await somewhere during the recursion. By forcing a step to be asynchronous, the stack count will be reset.