.app TLD audit hub
Google-operated, HSTS-preloaded TLD aimed at mobile and web applications.
Like .dev, the .app TLD is operated by Google Registry and is hardcoded into Chrome's HSTS preload list, meaning HTTPS is mandatory at the browser level. It launched to the public in 2018 after Google paid roughly $25 million in the new-gTLD auction. The intended audience is squarely the mobile and web application space — startups landing pages, app marketing sites, deep-link domains for mobile attribution, and progressive web app shells. Pricing sits in the same band as .dev and the namespace is broadly available because adoption was slower than initially projected. From an operational view there are no extra restrictions beyond the HSTS preload requirement, and DNSSEC, registry-lock and WHOIS privacy work normally. Linear chose .app for linear.app, Cash App uses cash.app — the common pattern is a brand that wants the noun-as-domain effect. SEO treats .app as a generic gTLD with no geotargeting bias. Our checker pays particular attention to redirect handling on .app domains: apex-to-www-to-CDN chains can compound certificate validation issues, and the lack of an HTTP fallback turns small misconfigurations into hard outages.