PDF offers a stable container for embedded video with predictable offline distribution but variable viewer support. MOBI (and more accurately, modern Kindle formats like AZW3) can support video through HTML5 workflows but suffers from device heterogeneity and conversion pitfalls. For widest reach, host video externally with robust fallbacks and accessible transcripts; embed only when offline availability or a controlled viewer environment is guaranteed.
Platforms in the "mobi" ecosystem—like v-s.mobi, followmobi, or findmobi—are often viewed with skepticism by cybersecurity experts and users. vs mobi videos work