Android 11 Introduces DNS-over-HTTP/3 Support

Google has announced the addition of DNS-over-HTTP/3 (DoH3) protocol support in Android 11 and later versions of its mobile operating system. This update is designed to improve the privacy of DNS queries and boost overall performance. Some devices running Android 10 will also receive this new functionality, provided their manufacturers have previously implemented system updates via the Google Play Store. End users do not need to take any action to enable this feature—Android will handle everything automatically.

What Is HTTP/3 and Why Does It Matter?

HTTP/3 is the third version of the Hypertext Transfer Protocol, built on QUIC—a multiplexed transport protocol that uses UDP instead of TCP, as in previous versions. This new protocol eliminates the so-called “head-of-line blocking” issue, which slows down data transmission if a packet is lost or reordered. This problem is especially common with mobile devices and frequent network switching.

Improvements Over Previous DNS Protocols

Earlier, Android 9 and later versions supported DNS-over-TLS (DoT), which improved DNS query privacy but inevitably slowed down DNS requests due to the extra resources required for encryption. Additionally, DoT required renegotiating a new connection every time the network changed. In contrast, QUIC can resume a suspended connection in just one round-trip time (RTT)—the time it takes to send a signal and receive confirmation that it was received.

As a result, DoH3 addresses many of the performance issues inherent to DoT. According to Google’s tests, DoH3 improves median query times by 24%, and in some cases, by up to 44%.

Additional Benefits and Future Plans

Another advantage of DoH3 is the use of a DNS resolver written in Rust, which is expected to significantly reduce the risk of vulnerabilities. DNS-over-HTTPS is already widely supported by many DNS providers to enhance privacy during DNS queries. With Google now supporting DNS-over-HTTP/3 and DNS-over-QUIC—both proposed standards—these technologies are likely to see even broader adoption among DNS providers soon.

For now, Android devices launching with this feature will use Cloudflare DNS and Google Public DNS, both of which already support DNS-over-QUIC. In the future, Google plans to add support for other DoH3 providers using Discovery of Designated Resolvers (DDR), which will allow Android to automatically select the best provider for a given configuration.