You can't actually view the DNS cache on mobile, but you can flush the cache and thereby fix any DNS or "timing out" errors you have encountered. Make sure your browsers in particular are closed. Scroll until you find the "Wi-Fi" menu. For an Android, find the "Wireless and Networks" menu in "Settings". Wait until your data indicator appears in the upper left-hand corner of the phone. If you have an Android, tap the "Wi-Fi" switch to turn the wifi off. Wait until the wifi icon appears, then return to the "Settings" menu. Find "Airplane Mode" at the top of your Settings menu on iPhone. Be sure to wait a few moments (for the wifi indicator in the upper left-hand corner to disappear) before turning Airplane Mode back off again This will reset your network settings, thereby enabling the DNS cache to flush. For Android, select "More" in the Settings menu to access the Airplane Mode setting toggle. This will turn off your phone and flush your DNS cache. Leave your phone off for at least 15 seconds. For Android, you need to hold down the "Power" button, then tap "Power off" in the resulting menu. This will turn your phone back on. Use your phone's browser to visit any site where you encountered a DNS error. You should now be able to access the site! Loading your frequently-used sites for the first time after a DNS flush will take longer than usual, since your DNS cache is being updated.
Close all apps to prepare to flush your DNS cache. Open the "Settings" menu. Select the "Wi-Fi" tab, then swipe the "Wi-Fi" switch to the left. Swipe your phone's wifi switch back on. Turn "Airplane Mode" on, then off again. Hold the "lock screen" button down, then swipe the "Slide to Power Off" button to the right. Hold down the "lock screen" button until the screen lights up. Confirm that your DNS cache flush worked.