Open Control Center and tap Flashlight. If the button is missing, add it back or try asking Siri to turn the light on. If the iPhone shows a temperature warning, turn it off, move it away from direct sunlight, and let it cool before testing again.
01Try a different way to switch on the light
Section linkOn an iPhone with Face ID, swipe down from the top-right corner for Control Center. On an iPhone with a Home button, swipe up from the bottom. If the flashlight works from Control Center or Siri, check the control you originally tried. For example, if you only lost the Lock Screen button, you can still use Control Center.
02Let a hot iPhone cool, then test again
Section linkIf the problem started after using the camera in the sun or leaving the iPhone somewhere hot, move it somewhere cooler. Apple says the camera flash can temporarily become unavailable when the device gets too warm. Test again once the phone cools.
03Compare the flashlight with the camera flash
Section linkRemove any case or camera accessory that could cover the rear flash or place a magnet near the camera. Restart the iPhone and test the flashlight from Control Center. Then try a photo with the camera flash set to On, since Auto may skip the flash in a bright room. If both tests still fail, tell Apple Support which controls you tried and whether the rear camera can take a photo.