“Hi, there, recently I upgraded my iPhone 7 to iOS 11, then I found that I can't use safari on my iPhone. I can't figure out what happened, can anyone help?”
We've heard many iOS users about that they can't use Safari or other apps after they upgrade their iOS system. This may be a bug or caused by the wrong operation during an upgrade process. While don't need to worry, normally after some simple adjustment and checking, you will fix this little problem.
1. Change the iPhone connected network
The first thing you can do is to change your network. Because the network you usually use may suddenly occur with the unknown problems which lead your safari can't work.
Just go to Settings > Wi-Fi > Turn off your Wi-Fi then turn on again, or choose another network, after connecting check whether your safari can be used or not. If your iPhone is connecting with cellular, you can turn off your Cellular Data to connect to Wi-Fi. Under the cellular connected condition, it can't be ruled out the problem of your carrier.
2. Reset network settings
If your safari doesn't work, it may be the problem of wrong network settings.
Go to Settings > General > Reset > Reset Network Settings.
Tip: This method will erase all your Wi-Fi login information. After resetting the network settings, don't forget to enter your password to log in your Wi-Fi again.
3. Clear safari cache, cookies, and history
If it is very slow to search in Safari, then you may need to clear your safari cache, cookies or history, which are the common reason to slow down internet speed.
Just go to Settings > Safari > Scroll down to tap Clear History and Website Data. But please notice that you will lose all your browsing history, login information and customized data stored in safari.
4. Restart your iPhone
After you upgrade your iOS system, you can restart your iPhone to release all your processes and then open your safari, it may work again.
It is easy to lose data after your upgrade your Phone to a new iOS version, so we suggest you do a backup of your important files before you do upgrade. With EaseUS MobiMover Free you can easily back up your iPhone data to computer and then transfer them back to your phone.
As the first totally free iPhone transfer software in the world, EaseUS MobiMover Free not only can back up your iPhone/iPad but also share files between iOS devices and sync computer data to your iPhone/iPad for absolutely free. The brand new iPhone 8/8 Plus/X and other iPhones with iOS 11 are perfectly supported.
Step 1. Run EaseUS MobiMover and connect your device to the computer. Select the "Backup Manager" pattern in the main interface. Then, select "Backup" to continue.
Step 2. EaseUS MobiMover will display all the iPhone files that are available for backing up. Just select all files by ticking the box next to the "Select All," and then click on "One-Click Backup" to proceed.
Step 3. EaseUS MobiMover will start to back up iPhone files to your computer immediately. Don't suspend the USB connection while backing up.
Once you've made a backup, you can restore this backup to your device when you need it. But note that this will erase your device and get everything replaced by what's in the backup. If you do mind this, just try to use "Phone to PC" feature to back up your device instead.
If you want to know how to transfer files back to your iPhone from computer, you can check the complete tutorial and the other way of transfer.
Related Articles - ALSO ON EaseUS SOFTWARE
iPhone Not Showing up in iTunes? 6 Working Solutions Here!
How to Fix iOS 11 Flashlight Not Working on iPhone and iPad
How to Restore iPhone From iCloud Backup 
[Quick Steps] How to See Blocked Numbers on iPhone? 3 Effective Solutions Here