The online audio speed changer tool changes the playback speed (tempo) and key (pitch) of music independently. The tool is ideal for changing the playback speed and/or key for song transcriptions, instrumental training (piano, guitar, violine, flute, ...), vocal training, but also for language learning.
To truly understand why the modding community overwhelmingly says "just use nodpi," you need to understand Android resource qualifiers.
Original YouTube Vanced introduced the concept of "portable" versus "root." A version (often called non-root ) could be installed alongside the stock YouTube app. It used a modified microG service to spoof Google login. This version sits in your app drawer as "YouTube ReVanced" while the official "YouTube" remains untouched. youtube revanced dpi or nodpi portable