Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts and first/last seen dates.

27 hosts · 296 ms

HostCertsFirst seenLast seen
rootly.com 41 2026-04-26 2026-10-09
*.rootly.com 26 2025-07-04 2026-10-11
knowledge-base.rootly.com 2 2026-04-07 2026-09-07
g.rootly.com 8 2026-06-01 2026-09-27
staging.rootly.com 2 2026-02-18 2026-07-24
webflow-staging.rootly.com 10 2026-05-18 2026-09-13
*.staging.rootly.com 9 2026-04-25 2026-08-21
alerting.staging.rootly.com 2 2026-02-14 2026-07-31
internal.alerting.staging.rootly.com 2 2026-02-14 2026-07-31
assets.staging.rootly.com 8 2026-05-04 2026-08-31
*.us.staging.rootly.com 2 2026-10-09 2026-10-09
alerting.rootly.com 2 2025-12-09 2026-10-01
internal.alerting.rootly.com 3 2025-12-07 2026-10-01
outrch.rootly.com 6 2026-04-17 2026-09-29
api.rootly.com 2 2026-02-19 2026-07-22
upflow-email.rootly.com 5 2026-05-02 2026-08-30
status-io.rootly.com 6 2026-04-24 2026-09-09
status-app.rootly.com 14 2026-04-17 2026-10-12
*.external-sp.rootly.com 13 2026-05-10 2026-09-05
84ac9928881d6fc082ee82fbc876053c364b34b8.external-sp.rootly.com 14 2026-05-29 2026-09-25
docs.rootly.com 17 2026-05-03 2026-09-01
webhooks.rootly.com 2 2026-02-19 2026-07-22
*.us.rootly.com 3 2026-10-09 2026-10-09
status.rootly.com 5 2026-05-20 2026-09-16
support.rootly.com 1 2026-06-02 2026-06-02
webflow.rootly.com 9 2026-06-12 2026-10-08
security.rootly.com 12 2026-05-22 2026-09-17

Programmatic access: API GET /v1/hosts/rootly.com (API key for paging).

Shown here: hostnames with a certificate that is valid now or expired within the last 90 days. The full history since 2013 — hostnames whose last certificate expired earlier — is a Pro plan method: GET /v1/hosts-history/rootly.com.