Tells browsers how to connect: HTTP/3, alternative endpoints, ECH.
Short answer
The HTTPS record (a form of SVCB) lets a site tell browsers, before they connect, which protocols it supports (for example h2 and h3), alternative hosts and ports, IP hints and Encrypted Client Hello keys. It can also act as an alias at the zone apex, which CNAME can’t.
- Type
- HTTPS
- Code
- 65
- Defined in
- RFC 9460
- IANA description
- SVCB-compatible type for use with HTTP
- Field: Priority
- 0 = alias mode, 1+ = service mode
- Field: Target
- “.” means the owner name itself
- Field: Parameters
- alpn, port, ipv4hint, ipv6hint, ech…
How it works
Large CDNs publish it automatically. A browser that understands it can skip a round trip or start with HTTP/3 directly.
Example
example.com. 300 IN HTTPS 1 . alpn="h3,h2" ipv4hint=192.0.2.10
Example uses reserved documentation names and addresses (RFC 2606, RFC 5737, RFC 3849).
Common mistakes
- An HTTPS record advertising h3 on a server that doesn’t speak HTTP/3.
How to check yours
A browser that supports the record looks it up alongside A and AAAA. If it lists protocols or hints that no longer match the server, some visitors may fail to connect while others are fine, so when you move a site off a CDN make sure its HTTPS records go with it.
Related record types
Sources
Sources
- IANA: Resource Record (RR) TYPEs registry · checked 5 Oct 2026
- RFC 9460 · checked 5 Oct 2026