Tick these off before trusting any result below.
Run the page twice: once with the allowlist off (that's T1), once with it on (that's T2). The results box at the bottom has a field to say which run this is.
The real app needs three external origins, not just one. If Family Link's allowlist blocks any of them, that part of the app dies. This runs automatically on load.
These are known ad-heavy videos embedded from www.youtube.com/embed/… (session-aware — deliberately
not the nocookie domain). Load each one, watch the first ~15 seconds, and record whether an ad played.
Pass = no pre-roll on any of them.
Useful for checking a video you actually plan to put in the playlist.
Diagnostic only. The real app must never use youtube-nocookie.com — it deliberately
withholds the session cookie, which would defeat Premium. It is here for one reason: if T1 shows no ads
and this control does show ads, that proves the Premium session is what's riding through, rather
than the test videos simply being ad-free today.
This page ships a real manifest + service worker, so it is installable exactly like the finished app will be.
If the button stays disabled, Chrome did not offer an install prompt — use ⋮ → Add to Home screen
manually, then open it from the home screen and check whether “Display mode” above reads standalone.
A plain shortcut is an acceptable degradation per the spec.