Why somtum.fun?

somtum.fun is a free, fan-run osu! server. Here's what you get by playing here, and what runs it.

At a glance

• A custom-built bancho core: our own osu! server backend, developed by blueskychan_ and Lilian. It isn't bancho.py or g0v0 (see below).
• One account everywhere: the same account, profile and friends in TumThai (osu!lazer), osu!(stable) and the old 2008-2015 clients.
• osu!lazer sees osu!(stable) scores, like on osu!: one leaderboard per map, whichever client you play on.
• Old clients welcome: 75 osu! builds from 2008 to 2015, rebuilt to connect here.
• Built-in pp calculator: pp for every play, worked out on the server, including Relax and Autopilot, and a live pp counter in osu!(stable) through the Somtum Patcher.
• Earn custom medals the community asked for, on top of osu!'s own.
• More to play: Relax and Autopilot boards, osu!dan courses, the Daily challenge and Map of the day. Custom lazer rulesets are coming next.
• Frequent updates: we fix and add things all the time; see the changelog.
• Free, always.

One account for every osu!

• TumThai, our version of osu!lazer, for Windows, Linux, macOS and Android. It updates itself.
• osu!(stable), today's client, through the Somtum Patcher or the Somtum Launcher.
• osu! from 2008 to 2015: play the client you started with.

Your profile, friends, scores and rankings are the same in all of them and on this website. See How do I connect?

More ways to play

• Relax and Autopilot with their own leaderboards, rankings and pp, in TumThai and osu!(stable). See Relax and Autopilot and Performance points.
• osu!dan: osu!mania dan courses with real rules (no pausing, accuracy, mods), and clears on your profile.
• Daily challenge and Map of the day.
• Custom medals: ask for one on the medals page, and our Medal Team adds the good ones for everyone to earn.
• Our own beatmaps and ranking: mappers can upload sets here, and our nominators rank and love maps on BN Management (see Beatmap ranking procedure).
• Tournaments, with the tournament client.

Fair play

Scores from osu!(stable) and the old clients only count with our anti-cheat running, and replays are checked after you play. Cheaters are restricted, and you can appeal if you think we got it wrong. TumThai and the Somtum Patcher are the only ways in whose scores count, so everyone plays on the same terms.

Our own server, not bancho.py or g0v0

somtum.fun doesn't run on bancho.py or g0v0, the server software many other private servers use. It runs on our own, self-developed osu! server backend.

• The game server is TomYum, our custom-built bancho core in C# (.NET), developed by blueskychan_ and Lilian. One server speaks to osu!lazer, today's osu!(stable) and the old 2008-2015 clients alike, and works out pp itself. It's open source; its documentation is at docs.somtum.fun.
• The website is our fork of osu-web, the same software as osu.ppy.sh. That's why profiles, beatmap pages, rankings, the forum and the API v2 look and work like osu!'s.
• For lazer, we run ppy's own open-source spectator and score-processing servers next to TomYum, so multiplayer, spectating and replays work as they do on osu!.
• bancho.py: somtum.fun ran on it until 12 October 2026. When we moved to TomYum, your account, scores and custom medals came along. Tools made for bancho.py servers still work through our bancho.py API.
• g0v0 is a separate osu!lazer server project. We don't use any of it; TumThai talks to our own servers. Its client can still connect (see Connecting with another lazer client), but its scores aren't submitted.

Ready? Head to the download page, or start with the FAQ.