The .app domain
.app is HTTPS-only: it is on the HSTS preload list, so browsers require a valid TLS certificate. A lapsed certificate doesn’t just warn — it blocks the site.
Good to know
- Operated by Google Registry
- HSTS-preloaded — HTTPS is mandatory
- SSL monitoring matters more here than on most TLDs
Monitoring a .app domain with Domnr
Whatever registrar your .app domain lives at, Domnr keeps an eye on the things that quietly break:
- Renewals & expiry — track the WHOIS expiry date so a .app domain never lapses.
- DNS & nameserver changes — get alerted when records change.
- SSL certificates — catch expiring certificates before HTTPS breaks — and .app requires HTTPS.
- Uptime — know the moment a site goes down.