Reader mode helps remove clutter, ads and distractions from websites. Many smartphone manufacturers have integrated this feature in the stock web browser on their devices. This feature can also be found in Safari for mobile. Here’s how you can enable Reader View in Safari on iPhone and iPad.
Turn on Reader Mode in Safari on iPhone
Launch Safari on your iPhone. Open the web page you like to read. If the page is very long, wait a second for it to load. After that you should see a small icon (double letters AA) before the website address. Tap that icon to reveal the drop-down menu. Choose Show Reader View from the menu to enter reader view mode in Safari browser on your iPhone. After that you will find all the clutter, ads and distractions are disappeared from the web page you are on. You’ll then see a simple screen of text and images. Text becomes white, background turns to be black. Reader View mode also provides users more options to customize how the web page looks, including font size, font style, background color.

To disable reader mode, simply touch the two A’s icon, choose Hide Reader View from the drop-down menu list.
Reader mode with other browsers
Except Safari, many third-party web browser also integrated this feature, notably the Alook web browser. You can refer to this guide to activate reader mode in Alook browser on iPhone.