What is IRCv3? The quiet modernization of IRC
Updated June 4, 2026
The IRC protocol was standardized in RFC 1459 (1993) and RFC 2812 (2000), and then — officially — froze. IRCv3 is the community working group that has spent the years since retrofitting modern features onto the protocol without breaking thirty years of existing software.
The trick: capability negotiation
IRCv3's core mechanism is CAP: at connection time, client and server
negotiate which extensions both sides support. Old clients ignore it all and
work exactly as in 1999; new clients light up extra features where available.
This is why the modernization has been so quiet — nothing broke.
The features that matter
server-time — messages carry real timestamps, so replayed history (from
a bouncer or the server) lands at the
correct time instead of "now". The single most important tag in practice.
sasl — authentication during connection, before joining channels. Now
simply how you log in on modern
networks.
chathistory — clients can request past messages from the server. On
servers that implement it with storage (Ergo, soju), scrolling up just works,
bouncer or not. This is the feature that removes IRC's most famous limitation.
message-tags + msgid — arbitrary metadata on messages, the foundation
for typing notifications (+typing), reactions and replies (+draft/react,
+draft/reply) and similar client-visible niceties.
multi-prefix, away-notify, account-tag, echo-message — a family of
small quality fixes: accurate user lists, away status updates, knowing which
account sent a message, and seeing your own messages as the server saw them.
Bot mode (+B) — a standardized way for bots to identify themselves,
which networks increasingly require by policy.
Who implements it
Effectively everything maintained: servers (Ergo leads on completeness; solanum, InspIRCd and UnrealIRCd implement large subsets), bouncers (soju was designed around IRCv3; ZNC supports the essentials), and clients (goguma, Halloy, gamja, WeeChat and others). Big networks adopt conservatively — Libera.Chat supports a solid core set — while small modern networks running Ergo can offer nearly the full Discord-adjacent experience over plain IRC.
Why it matters
IRCv3 is the answer to "why not just use something modern": increasingly, IRC is something modern, underneath the same protocol that has run since 1988. If you are choosing a client or a server to run, the breadth of IRCv3 support is now one of the most useful things to compare.