Google Public DNS is a recursive DNS resolution service that converts familiar domain names (such as expressvpn.com) into IP addresses that computers can understand. This article will explain how the service works, its key features, the differences from other options like Cloudflare, and provide detailed setup instructions on various devices.

What is Google Public DNS?

Google Public DNS is a free public DNS service provided by Google, allowing users to utilize a domain name resolution system instead of relying on the default DNS of their Internet service provider (ISP). This service uses the global anycast network to route queries to the nearest data center, thereby reducing latency and increasing stability compared to some traditional DNS systems.

In terms of security, Google Public DNS automatically applies DNSSEC authentication to ensure that DNS responses are not spoofed or altered during transmission. Additionally, the service supports encrypted DNS protocols such as DNS over HTTPS (DoH) and DNS over TLS (DoT), which help protect query data from being tracked, although these features need to be manually enabled on the device or browser.

How Google's DNS System Works

When you enter a domain name into your browser, the device sends a request to the DNS resolver to find the corresponding IP address. Google Public DNS handles this entire process through a series of steps:
First, the system checks the data in its cache. If it's available, the result is returned immediately.
If not, the query is sent through the DNS hierarchy, including the root server, top-level name servers (TLDs) like .com, and finally the domain's authority server.
After receiving the IP address, the system returns the result to the device and stores it in the cache for later use.
Thanks to the anycast mechanism, queries are always routed to the nearest server, helping to distribute the load efficiently and increase response speed.
Distinguishing between Google Public DNS and Google Cloud DNS

These two services have completely different purposes:
Google Public DNS: Used to resolve domain names for end users.
Google Cloud DNS: A DNS hosting service for website administrators and developers, helping to manage DNS records for domain names.
Google DNS Addresses

Google provides standard, easy-to-remember DNS addresses:
IPv4: 8.8.8.8 and 8.8.4.4
IPv6: 2001:4860:4860::8888 and 2001:4860:4860::8844
Whether using IPv4 or IPv6, these addresses point to the same system and provide equivalent functionality. Users can configure both simultaneously for increased flexibility.
Key Features of Google DNS

Google Public DNS integrates several important capabilities:
Recursive DNS resolution with intelligent caching mechanism
Global anycast infrastructure to speed up queries
DNSSEC authentication to ensure data integrity
Support for DNS encryption (DoH and DoT)
Capability to handle high traffic thanks to a distributed system
Provides standard, easily configurable public IP addresses
Transparent logging and privacy policies
Comparison with other DNS services
Different public DNS resolvers vary in performance, security levels, and data policies. For example:
Cloudflare (1.1.1.1) focuses on privacy with short log retention times
OpenDNS offers content filtering and parental controls
Quad9 focuses on blocking malicious domains
Choosing the right service depends on specific needs such as speed, security, or content control.
How to Change DNS on Your Device

Changing DNS essentially means replacing the default DNS address with Google's address:
On Windows: Access network properties and enter 8.8.8.8 and 8.8.4.4
On macOS: Configure in the Network section of System Settings
On iOS/Android: Manually set up DNS for each Wi-Fi network or use Private DNS (dns.google)
On your router: Configure directly to apply to all devices on the network
How to Check if DNS is Working

After setup, you can use the nslookup command to check the DNS server being used. If it displays the correct Google address, the configuration was successful.
Effective for Gaming and Video Streaming

Google Public DNS can help reduce initial connection times, such as faster login or server finding. However, it does not reduce ping in games or increase data download speeds after connection.
For streaming, DNS mainly affects the initial connection step to the CDN server. In some cases, the ISP's DNS may be faster due to the use of internal caching, so actual performance depends on the specific network and the user's geographical location.