AutoScroll bookmarklet - from https://appdocumentary.com/2014/10/14/how-to-automatically-scroll-a-web-page-for-buttery-smooth-screen-captures/

AutoScroll.js

javascript:(function(n,t)%7Bt%5B%27true%27%5D%3Dn%3Bvar i%3Dfunction(n,t,i)%7Bvar r%3Dn.style%3Br.webkitTransition%3Dr.transition%3Di%2B%27s%27%3Br.webkitTransitionTimingFunction%3Dr.TransitionTimingFunction%3D%27ease-in-out%27%3Br.webkitTransform%3Dr.Transform%3D%27translate3d(0, %27%2B-t%2B%27px, 0)%27%7D%3Bvar r%3Dfunction()%7Bvar n%3D%5B%5D.slice.call(arguments)%3Bvar t%3Dn.shift(),i%3Dn.shift(),r%3Dn%3BsetTimeout(function()%7Bi.apply(null,r)%7D,t*1e3)%7D%3Bvar e%3Dfunction(n,t,i,e)%7Br(t,o,i,e)%7D%3Bvar a%3Ddocument.getElementsByTagName(%27body%27)%5B0%5D%3Bvar o%3Di.bind(null,a)%3Bvar s%3De.bind(null,a)%3Bvar l%3Dfunction(n)%7Bvar t%3D%27Enter delay (in seconds), distance to scroll (in pixels) and the scroll duration (in seconds).%5Cn%5CnRun the script a second time with options 0 0 0 to reset the page.%5Cn%5CnExample:%5Cn%5Cn1 800 5%27%3Bif(n)%7Bt%3Dn%2B%27%5Cn%5Cn%27%2Bt%7Dvar i%3Dprompt(t)%3Bif(i%3D%3D%3Dnull)%7Breturn%7Dif(/%5Cd%7B1,%7D %5Cd%7B1,%7D %5Cd%7B1,%7D/.test(i))%7Breturn i.split(%27 %27)%7Dreturn l(%27Woops. Input invalid: %27%2Bi)%7D%3Bvar u%3Dfunction()%7Bvar n%3Dl()%3Bif(n)%7Bs.apply(null,n)%7D%7D%3Bu()%7D)(%7B%7D,function()%7Breturn this%7D())%3B