Problem is, the browse pages have a 4x3 grid of live WebGL previews (rather than e.g. static images) of the shadertoys.
On my home desktop pc (win10, i4790k@4Ghz, GTX1070, 24 GB) running Chrome this means that inevitably, on page one or two, at least one of the shadertoys will use so much GPU computation that it starves out all other functionality, like being able to switch tabs etc.