CRDTs
Last Updated: June 12, 2026
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A Conflict-Free Replicated Data Type is a data structure designed to be replicated across many nodes, updated independently, and merged into the same final state without coordination.
Each replica accepts writes locally. When replicas exchange state, a merge function combines their copies into the same result regardless of the order or number of merges. There is no winner, no lost update, and no application-level conflict resolution.
CRDTs are useful for:
- multi-region databases that accept writes in every region
- offline-first applications that sync when reconnected
- collaborative editors with many concurrent authors
- shared carts, counters, and presence indicators
- replicated configuration or feature flag systems
CRDTs do not eliminate the cost of replication. They move that cost into the data type and the metadata that travels with the data.