HTTPS

HTTPS Record

Active

The HTTPS record (a special case of SVCB) provides service binding information for HTTPS connections.

name TTL IN HTTPS priority target [params]

In one line

The HTTPS record (a special case of SVCB) provides service binding information for HTTPS connections. It can specify alternative hostnames, ports, and TLS parameters including ALPN protocols (h2, h3), ECH (Encrypted Client Hello) keys, and IP address hints. Browsers query HTTPS records before connecting, enabling HTTP/3 discovery and reducing connection latency.

Description

HTTPS records (RFC 9460) combine and supersede several older mechanisms. They let a zone publish that HTTPS is the only way to connect (replacing HSTS for new connections), advertise HTTP/2 and HTTP/3 ALPN tokens (replacing Alt-Svc), publish ECH parameters for encrypted SNI, and provide address hints to avoid an extra DNS roundtrip. Chrome and Firefox query HTTPS records automatically for every HTTPS URL.

Examples

Basic HTTPS record

shell

example.com. 3600 IN HTTPS 1 . alpn="h2,h3"

With ECH and IP hints

shell

example.com. 3600 IN HTTPS 1 . alpn="h2,h3" ech=<base64> ipv4hint=192.0.2.1 ipv6hint=2001:db8::1

Query HTTPS record

shell

dig example.com HTTPS

Related Record Types

SVCB A

Specification

RFC 9460 – DNS HTTPS record specification →