Now in open beta

Code together,
conflict-free

Real-time collaborative editing powered by CRDTs. No merge hell, no polling. Just open a room and code.

Free & open source — no account required

Fast
Syncs in under 50ms. WebSocket-native, no polling, no latency surprises.
Intelligent
Yjs CRDTs merge concurrent edits deterministically. Zero conflict resolution.
Collaborative
Live cursors with name labels, presence indicators, and room sharing in one click.
Live demo

Two cursors,
one editor

Watch Alice and Bob type simultaneously — no conflicts, no waiting, no refreshes. Just real-time magic.

A
Alice
B
Bob
+ invite
Room info
roomabc-123-xyz
languageTypeScript
connected2 / ∞
sync latency< 50ms
codeduo — collab.ts
collab.ts
room.ts
types.ts
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import { Doc } from "yjs";
import { WebsocketProvider } from "y-websocket";
 
const doc = new Doc();
const provider = new WebsocketProvider(
"wss://codeduo.dev", "room-1", doc);
 
// Real-time — zero conflicts
const text = doc.getText("editor");
text.observe(() => {
console.log(text.toString());
});
Connected2 users
TypeScriptUTF-8LF
<50ms
Sync latency
100%
Conflict-free
0 KB
Data on our servers
∞
Concurrent editors
Why CodeDuo

Built for serious
collaboration

Real-Time Sync
Changes propagate in milliseconds. No refresh, no polling — instant collaboration.
< 50ms latency
Live Cursors
See exactly where collaborators are editing. Color-coded cursors with name labels.
Per-user colors
Offline Resilient
Keep coding when disconnected. Edits queue locally and sync when you reconnect.
Zero data loss
Zero Conflicts
Yjs CRDTs merge concurrent edits deterministically. No manual resolution ever.
Deterministic merge
No Lock-In
Open source and self-hostable. Your data never touches our servers.
Self-hostable
Monaco Editor
Full VS Code editing experience — syntax highlighting, IntelliSense, multi-cursor.
50+ languages
How it works

Up in three steps

01
02
03
Create a room
Spin up a session in one click. Pick a language, name your room, and you're live.
$ curl -X POST /api/rooms
→ { "id": "abc-123" }
Share the link
Send your teammates a room URL. No sign-up required — just click and join.
codeduo.dev/room/abc-123
✓ Link copied to clipboard
Code together
Cursors appear in real time. Edits merge via CRDTs. Zero conflicts, zero friction.
// 2 users connected
Alice: line 14...
Bob: line 27...

Ready to code
together?

Create a room in seconds. No sign-up, no setup, no friction. Just share the link and start collaborating.

View on GitHub

Free & open source — no account required