Subbed
Subbed anime keeps the original Japanese voice acting, with subtitles. Many fans prefer it for the performances.
Dubbed
Dubbed anime replaces the voices with another language, often English. It is ideal when you want to keep your eyes on the pictures.
Where to switch
On most services, open the audio menu in the player. On some, the dub is listed as a separate version of the series.
Timing
New episodes usually arrive subbed first, and the dub follows a few weeks later.
