We all know that that the default YouTube app will turn the audio off as soon as you lock your screen. However, there is no setting to solve this in the default app, but there is a way to play videos on YouTube even after you lock the screen.
Moreover, in order to solve this, the company has launched YouTube Red last October. But there is a catch here! Meanwhile, it is a paid subscription by YouTube and only available in the US right now! The so-called YouTube Red provides advertising-free streaming of videos, offline and background playback of videos on mobile devices.
But there are ways to play YouTube videos with the screen off and we have mentioned it in the below point.
Step 1: Firstly, download the Mozilla Firefox app from Google Play Store on your Android smartphone.
Step 2: After the installation, open the Firefox browser and open the Youtube in it.
Step 3: Select the YouTube video you would like to play!
Step 4: The player will automatically start playing the track or video. Now you can exit the app or turn your screen off.