A simple setting change can get you extra brightness on web pages and documents
The Samsung Galaxy S4's Full HD SuperAMOLED screen is the best AMOLED display we've seen on a smartphone. However if you're noticing subpar brightness some of the time, there's an option in "Display settings" you might want to take a look at.
By default, the Galaxy S4 and many other Samsung devices ship with "Auto adjust display tone" turned on. You can find it under Settings > My device > Display > More settings. When enabled, it tweaks the display brightness based on the on-screen image to avoid burning through an excessive amount of juice. Most of the time you might not notice this, but there's an easy way to see its effects.