To record an iPhone demo in Tella, connect your iPhone to your Mac with a cable, show its screen in a QuickTime Player New Movie Recording window, and record that window in Tella. You can also screen record on the iPhone and upload the file.
Wireless screen mirroring (AirPlay from your iPhone to your Mac) doesn’t work for recording on recent versions of macOS. The mirrored iPhone content shows up as a black rectangle in any screen recording. Apple blocks it at the system level, in every recording app, even though it looks fine on your Mac’s screen while you record. Use a cable and QuickTime, or record on the phone, instead.
Record your iPhone screen with QuickTime (wired)
You need an iPhone, a Mac, and a cable to connect them.
- Connect your iPhone to your Mac with a USB cable
- Open QuickTime Player on your Mac
- Choose File → New Movie Recording
- Click the arrow next to the record button and select your iPhone as the camera source
- Your iPhone screen will appear in the QuickTime window
- Record the QuickTime window using Tella (web app, Chrome extension, or Mac app)
Record on the iPhone, then upload
- On your iPhone, add Screen Recording to Control Center (Settings → Control Center)
- Open Control Center and tap the record button to capture your iPhone screen
- When you’re done, stop the recording. It’s saved to your Photos
- Transfer the video to your computer (AirDrop is quickest) and upload it to Tella
Edit your iPhone demo
After recording, use Tella’s editor to trim the beginning and end, and resize the layout to fit your iPhone screen. 
