If you use iPhone 8, iPhone 8 Plus, iPhone X, iPhone XR, iPhone XS, iPhone XS Max, iPhone11, iPhone Pro or iPhone 11 Pro Max, you can use the iOS 11 screen recording function directly. Because those iOS devices are released later than the iOS 11 update. In another word, you can screen record on iPhone 8 and later with the built-in iOS screen recorder.

To screen record on iPhone 7 and earlier models, you need to check which iOS version you use at present. Currently you can create a screen recording on iOS 11 and later versions.

Step 1: Add Screen Recording to Control Center
Open the Settings app. Choose Control Center within the iPhone Settings app. Tap Customize Controls to access all options. Then tap the green + icon before Screen Recording. It means the iOS screen recording feature is moved to the Include section from More Controls.

Step 2: Access iPhone Control Center
Navigate to the page you want to record. For iPhone 8 and earlier users, scroll up to get the Control Center menu. If you use iPhone X or later devices, you can pull down the Control Center menu from the top right corner instead.

Step 3: Enable Do Not Disturb
If you want to screen record on iPhone without popups or other disturbing issues. You had better switch on Do Not Disturb to close down all notifications temporarily. You can tap on the crescent moon icon and specify more details.

Step 4: Record iPhone screen with sound
Press deeply on the Screen Record button. Choose Microphone to screen record on iPhone with audio. Now tap Start Recording to record app screen or video on iPhone. A countdown timer pops up. Later, iPhone will start recording a video of your iPhone’s screen automatically.

Step 5: Stop recording screen on iPhone
When you want to stop recording on iPhone, you can swipe up or down to get the Control Center. Tap the Record button to stop screen record on iPhone without red bar. Tap Stop in the popping-up dialog saying Stop Screen Recording. The recorded iPhone screen video will be saved in the Photos app by default.

Reading more: https://www.vidmore.com/record-video/record-screen-on-iphone/