How to adjust scroll distance in browsers?

November 14, 2017 11:14 AM

How can I use Chrome or Firefox's advanced about:config settings to tweak how many pixels/lines are shown for each time you do a full-screen scroll with the spacebar? I'd love to shorten the scroll by about 5% of the window height, but tried everything and can't seem to get it to work (or are there extensions to do this?)

I have to do a repetitive task in a browser, using a web app that has about 50px of UI covering content. I scroll through thousands of pages, but every few pages, I have to scroll back a little, since the web app's UI covers up the content in spots. Ideally, I'd love to set my browser's fullscreen scroll distance to maybe 90% or 95% or a certain number of pixels short. I'd be fine seeing a line or two of repeated content, the problem is missing content entirely is both annoying and time-consuming to scrollback to see.

I've played with every mention of "scroll" in about:config on the newest Firefox Quantum browser, but still can't seem to tweak this in any way. I can't seem to get a google search to give me an answer either since it's mostly web developers trying to make auto-scrolling methods in web apps. Anyone have any ideas?

posted by mathowie to Computers & Internet (2 answers total)

Best answer: In the current version of Firefox, the amount that the "page down" command scrolls is the height of the page minus 2 "lines" or 10%, whichever is smaller (so on large pages, it's the height minus 2 "lines").

The definition of a "line" depends on the page's font size, down to a minimum of 5 pixels. That last number can be customized using the mousewheel.min_line_scroll_amount preference in about:config. So if you increase that preference to, say, 50, that will shorten the scroll distance to (height − 100 pixels) on most pages. However, it will also affect other things, like mouse wheel scrolling, which you might not want.

As far as I can tell from reading the code, there's no other preference that influences this scroll distance in Firefox.
posted by mbrubeck at 11:30 AM on November 14, 2017 [7 favorites]

Response by poster: Holy cow, thanks for this mbrubeck! I've been trying out dozens of extensions all morning, but this tweak (anywhere from 60-80) seems to do the trick. Oddly, it only works if I use the spacebar to scroll down a screen. If I use a funnction+down arrow keystroke, it doesn't seem to respect the setting, but I can switch to spacebar scrolling pretty easily.

Thanks again for helping me out, this has been bugging me for months with no answer!
posted by mathowie at 11:46 AM on November 14, 2017 [2 favorites]