Undernet: the 1992 giant that's still one of IRC's largest

Undernet is one of IRC's genuine survivors: founded in 1992 as a reaction against the instability and politics of the original network, it's still — in 2026 — among the largest IRC networks in the world, running around 16,000 concurrent users across some 5,600 channels. Unlike Libera or OFTC, it never narrowed to open source. Undernet is, and always was, a general-purpose network: communities, languages, regions, and chat for its own sake.

Connecting #

• Server: irc.undernet.org round-robins you to a member server. TLS on 6697 where the server you land on supports it.
• The network is a federation of independently operated servers across the US, Europe and beyond — a structure it pioneered and that's served it for thirty years.
• Help: #help.

The X service #

Undernet's signature is X — its channel-management service, the equivalent of ChanServ elsewhere but with its own history and culture. To register and manage channels you create an Undernet account (a CService username) on the network's website, then authenticate to X in your client:

/msg x@channels.undernet.org login YOURNAME YOURPASSWORD

X handles channel ownership, op access lists, and the persistence that lets a channel keep its operators and settings across the years. It predates the NickServ/ChanServ split that DALnet made famous, and does the same job its own way.

Who's there #

Undernet's strength has always been its breadth — large national and language-based communities, long-running social channels, and topic channels of every kind. It's less a "project support" network and more a place communities live. If you're looking for the official channel of an open-source tool, that's probably on Libera; if you're looking for a busy general chat community that's been stable since the 1990s, Undernet is exactly that.

Should you join? #

For your first IRC steps, or for project support, start on Libera.Chat. Come to Undernet for its communities, or simply to spend time on one of the few networks that was genuinely huge in 1995 and is still genuinely huge now — a piece of living IRC history that never stopped being busy. As always, register your nick (here, an X account) if you intend to stay.