8.8.8.8: Google Public DNS

8.8.8.8 is the primary IPv4 address of Google Public DNS, a free recursive resolver Google launched on 3 December 2009. It answers name lookups for anyone who points a device at it. Google announces the address by anycast from data centres worldwide, so your query reaches a nearby machine rather than one fixed server.

Who runs it, and why the address is memorable

The address sits in 8.8.8.0/24, part of a block Google acquired from Level 3. Google announces it from AS15169, the same autonomous system behind Search and Gmail. Four repeated octets make it easy to recall, which was the point: the launch post pitched the service as a faster, standards-compliant alternative to the resolver your ISP hands you over DHCP.

It is a recursive resolver, not an authoritative one. It does not hold the records for any domain. It walks the delegation chain from the root down, caches what it finds, and hands you the answer.

When you see it

• In ipconfig /all on Windows or scutil --dns on macOS, listed as a DNS server, because someone configured it manually.
• In a router’s WAN or DHCP page, where many people set it after reading a speed tip.
• In firewall logs as a destination on UDP and TCP port 53, or on port 853 for DNS over TLS.
• In resolv.conf on Linux servers and inside container images, where it is the standard fallback nameserver.
• In outage reports, where “try 8.8.8.8” is the usual first test of whether a name problem is local or upstream.

How to set it as your resolver

1. Windows: Settings, Network and Internet, your adapter, Edit DNS server assignment, Manual, IPv4 on, preferred 8.8.8.8, alternate 8.8.4.4.
2. macOS: System Settings, Network, your interface, Details, DNS, then add both addresses and remove the ones inherited from DHCP.
3. Linux with systemd-resolved: set DNS=8.8.8.8 8.8.4.4 in /etc/systemd/resolved.conf, then systemctl restart systemd-resolved.
4. Router: set it on the LAN DHCP settings so every device inherits it, rather than editing each device.
5. Encrypted: use dns.google for DNS over TLS, or https://dns.google/dns-query for DNS over HTTPS.

Privacy and policy

The Google Public DNS privacy notice states that temporary logs record the full client IP address and are deleted within 24 to 48 hours, while permanent logs drop the address and keep coarser location data for analysis. Google says it does not use Public DNS query data to target advertising and does not correlate it with a Google account.

One behaviour worth knowing: Google Public DNS supports EDNS Client Subnet, so it forwards a truncated prefix of your address to authoritative servers that ask for it. That improves CDN routing and reveals a rough network location to those servers. Cloudflare’s resolver does not send client subnet data by default, which is the main technical difference between the two.

What 8.8.8.8 is not

It is not a VPN, a proxy, or a filter. Changing your resolver to 8.8.8.8 does not hide your IP address from the sites you visit, and it does not stop your ISP from seeing which servers you connect to. It also does not block malicious domains. If a page loads slowly, the resolver is rarely the cause once the name is cached.

Point /dns-lookup at a hostname to see what 8.8.8.8 returns, and compare it against another resolver in the same view.