To download episodes for offline playback, you must use the official apps for these services on a mobile device or tablet:

The universal standard. It plays on almost any device (older TVs, phones, laptops) but results in larger file sizes for high-definition video.

Video files should strictly be in formats like .mp4 , .mkv , or .m4v . If a website prompts you to download an .exe , .msi , or .zip file to watch the show, abort immediately. These are almost always malware or ransomware.