FAQ

What is LoonDNS?

Free dynamic DNS. You claim a name like you.loondns.com and point it at your home/server IP — which LoonDNS keeps up to date even as your ISP changes it. Great for self-hosting, remote access, homelabs, and getting HTTPS certs on a changing IP.

How is it different from DuckDNS?

• Up to 25 names per account, each with A, AAAA and wildcard.
• Speaks three protocols: DuckDNS-compatible, standard dyndns2 (routers/ddclient), and a clean REST API.
• First-class Let's Encrypt wildcard certs via DNS-01.
• Self-hosted on its own authoritative servers — no third-party DNS in the path.

Is it really free?

Yes. No cost, no ads. It runs on modest infrastructure; please don't abuse it so it can stay free for everyone.

How do I keep my IP updated?

Point any dynamic-DNS client at us, or run a one-line cron. The setup guide has copy-paste configs for routers, ddclient, OpenWrt, pfSense, Synology, Docker, Windows and more. Full details in the API spec.

Does my router work with it?

Almost certainly — LoonDNS implements the dyndns2 protocol. In your router's Dynamic DNS settings pick a custom/dyndns provider, set the server to loondns.com, username to anything, and password to your token.

Does it support IPv6 and wildcards?

Yes to both. Set an AAAA by passing an IPv6 address, and *.yourname.loondns.com automatically resolves to your name's address.

Can I get a wildcard TLS certificate?

Yes. LoonDNS serves the _acme-challenge TXT record, so Let's Encrypt DNS-01 (including wildcard *.yourname certs) works. Set the TXT via the API during issuance — see the spec.

How fast do changes take effect?

Records use a 60-second TTL, so a new IP is visible on the next query, with at most ~60s of downstream resolver caching.

What can I point a name at? Any rules?

A, AAAA and TXT records only. Don't use names for phishing, malware, or impersonating brands — see the acceptable-use policy. Abuse gets a name disabled fast; report it at /abuse.

Is my data private?

We store your account identity, your names and records, and the source IP of updates — only to run the service and handle abuse. We don't sell it. See the policy.