The docs have a quick search window. It seems the search feature is broken on www.numpy.org/devdocs/search.html but works on https://docs.scipy.org/doc/numpy/search.html. It was suggested on the mailing list this may be due to sphinx 1.8.0, as matplotlib pinned sphinx matplotlib/matplotlib#12183 to !=1.8.0 and sphinx is aware of the issue sphinx-doc/sphinx#5460 a fix is scheduled for sphinx 1.8.1