Operational Transformation
Last Updated: May 28, 2026
Operational Transformation (OT) lets multiple users edit the same document at the same time and end up with the same final state, with no locks and no waiting between users.
When an edit from one user arrives at another's replica, the system rewrites the incoming operation to account for what has happened locally since it was issued. Both replicas apply different sequences of operations and still converge.
OT is used for:
- real-time collaborative document editing
- multi-cursor code editors
- shared whiteboards and design tools
- collaborative spreadsheets
- any application where many clients send small, frequent edits to shared state
OT came out of groupware research in the late 1980s and is still the basis of Google Docs, Etherpad, ShareDB, and many enterprise editors.