I used to use a plugin called Spreader that does this for the browser. More recently I've started using QuickReader on my phone and I do by line (3 words per li

I used to use a plugin called Spreader that does this for the browser. More recently I've started using QuickReader on my phone and I do by line (3 words per line) with a larger font. The app really increases my reading speed and I highly recommend it.