Screencast apps focus on giving users a high quality video. A good screencasting tool should be light enough so that it doesn’t drag the system down, and it should be easy enough to use so that users don’t need to watch multiple tutorials to start recording with it. If you want to record a screencast with voice over on macOS you have two options. You can record the audio separately and add it to the video in post-production, or you can record the audio as you record your screen. If you’re looking to go with the second option, the default screen recording utility in macOS will do the job.
Screencast with voice over
On your Mac, open the screenshot utility. You can open it by searching for it in Spotlight, or you can open it from Launchpad. The trick is to access its UI and not just the quick screenshot feature. Once you see the screenshot utility’s bar, select the screencast option that you want to use.
The two options allow you to record the entire screen, or record just a select area of it.
Once you’ve selected a screencast type, click the Options dropdown next to it. You will see a long list of items that you can enable/disable. Under ‘Microphone’, select the mic that you want to use to record the voice over. After that, you can start recording your screen and all audio input detected by the mic will be recorded with it.
If you have multiple input devices that you want to record with, you can set up an aggregate audio device on macOS which basically combines multiple audio devices into one.
The final file that you get will be much larger than a file without any audio. macOS records the screen in the best possibly quality so you can rest assured that the audio quality will be just as good and hence the file will be larger. It will not make up for any background noise though. That’s something you have to take care of yourself. The audio quality is just how well the sound that’s detected is compressed in the video and what bit-rate it has, among other things.
You should note that one other option for audio is the ‘Background Music (UI sounds)’. Selecting this option will record the UI audio sounds you get when you interact with your system. For example, when you move files to the Trash on macOS, you hear a particular sound. That sound, and others like it will be recorded when this option is selected.