topic Obsoleted
Verified 2026-09-19 · registry updated 2023-10-20

HTTP registry: h2c

Hypertext Transfer Protocol version 2 (HTTP/2) (OBSOLETE)

Upgrade values negotiate an alternate protocol or capability at a defined HTTP boundary. The registry marks this value obsoleted; review compatibility before deploying it. h2c is obsoleted in HTTP Upgrade Tokens. Defining reference: RFC9113, Section 3.1.

httpregistryhttp-upgrade-tokenshttp-upgrade-tokens-1

Identifier (http)

h2c

Hypertext Transfer Protocol version 2 (HTTP/2) (OBSOLETE)

Validate the requested protocol and preserve authority and certificate checks. The registry marks this value obsoleted; review compatibility before deploying it.

This registry value is currently marked obsoleted by IANA. Follow the defining specification before sending, accepting, or proxying it.

IANA registry: http-upgrade-tokens/http-upgrade-tokens-1

Registry reference: RFC9113, Section 3.1

Permalink: https://merginit.com/reference/http/registry/http-upgrade-tokens/http-upgrade-tokens-1/h2c-198