YouTube Embed Matrix Test

Playlist under test:


Goal: open this file directly from file:// and see whether any embed combination works locally. Each tile uses a different embed host, query string, and/or iframe referrerpolicy.
Open Playlist On YouTube Open Canonical Embed URL
What to look for: any tile that actually renders and plays the playlist.
Common failure: YouTube error 153 or “Watch on YouTube”.
If one variant works, that gives us the exact local-file strategy to bring back into your main app.