Even if you have a server (or two) running your own DNS, to minimise service interruptions or outages it’s a great idea to have additional secondary DNS servers that are separate from your infrastructure.

Below in alphabetical order areĀ of some of the free secondary DNS providers that I have used, or currently still do.

1984

  • 4 DNS servers in Europe
  • Available on IPv4 only.
  • Also provides free Primary DNS.

Afraid

  • Single DNS server, Washington DC, USA.
  • Available on IPv4 and IPv6.
  • Provides some other paid services.

Hurricane Electric

  • 5 DNS servers that are anycast in multiple locations USA, Europe, Asia.
  • Available on IPv4 and IPv6.
  • Also provides free Primary DNS.

PUCK

  • Single DNS server in Chicago IL, USA.
  • Available on IPv4 and IPv6.

System NS

  • 2 DNS server hostnames, 3 IPs in Europe, 2 IPs in North America.
  • Available on IPv4 only.
  • Limit of 5 Domains per account.
  • Also provides free Primary DNS.

Trifle

  • Single DNS server in Ukraine.
  • Available on IPv4 only.

Twisted4Life

  • Single DNS server in Malaysia.
  • Available on IPv4 only.

Xname

  • 3 DNS servers in France.
  • Available on IPv4 and IPv6 (on one server).
  • Also provides free Primary DNS.

I try and keep this list regularly updated, please let me know if you have a suggested update.