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.

22 hosts · 165 ms

HostCertsFirst seenLast seen
opensea.io 66 2026-04-22 2026-10-02
*.opensea.io 31 2025-09-17 2026-10-02
partners-v2.opensea.io 10 2026-05-27 2026-09-22
blog-v3.opensea.io 10 2026-05-26 2026-09-22
mobile-beta.opensea.io 2 2026-06-11 2026-06-11
mcp-beta.opensea.io 12 2026-06-04 2026-09-30
dev-storage.opensea.io 3 2026-05-03 2026-08-22
auth.opensea.io 1 2026-05-27 2026-05-27
applink.opensea.io 4 2026-09-30 2026-09-30
graphql.opensea.io 1 2026-09-09 2026-09-09
learn.opensea.io 11 2026-06-10 2026-10-06
*.pro.opensea.io 18 2026-04-30 2026-08-26
mcp.opensea.io 22 2026-06-03 2026-09-30
docs.opensea.io 14 2026-05-18 2026-09-13
community-standards.opensea.io 7 2026-05-26 2026-09-21
partners.opensea.io 9 2026-05-26 2026-09-21
privy.wallets.opensea.io 16 2026-06-09 2026-10-06
*.testnets.opensea.io 17 2026-05-11 2026-09-06
status.opensea.io 4 2026-06-10 2026-09-30
wallet.opensea.io 4 2026-04-16 2026-08-19
privy.wallet.opensea.io 12 2026-05-15 2026-09-10
support.opensea.io 14 2026-04-19 2026-08-15

Programmatic access: API GET /v1/hosts/opensea.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/opensea.io.