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.

10 hosts · 256 ms

HostCertsFirst seenLast seen
sealsecurity.io 8 2026-04-14 2026-10-08
*.sealsecurity.io 2 2025-09-26 2026-08-27
login.sealsecurity.io 2 2025-10-31 2026-10-01
preview.app.sealsecurity.io 1 2026-07-06 2026-07-06
docs.sealsecurity.io 10 2026-04-21 2026-08-17
trust.sealsecurity.io 9 2026-05-18 2026-09-13
login-dev.sealsecurity.io 2 2025-10-31 2026-10-01
*.dev.sealsecurity.io 1 2026-01-29 2026-01-29
*.preview.dev.sealsecurity.io 1 2026-07-05 2026-07-05
www.sealsecurity.io 12 2026-04-13 2026-10-07

Programmatic access: API GET /v1/hosts/sealsecurity.io (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/sealsecurity.io.