Yjs

CRDT library for shared dataOpen source· verified Sep 2026

Represents shared documents as CRDTs, so edits from any number of clients merge automatically without conflicts or a central lock. Providers sync it over WebSockets, WebRTC, or IndexedDB for offline use.

Official site

Reach for it when

Real-time collaborative editors and whiteboards
Apps where offline edits must merge cleanly later

Worth knowing

Store the binary Yjs state as the source of truth — rebuilding a document from rendered HTML or JSON loses the history offline edits need to merge.

In stack playbooks

Collaborative editing (local-first): Yjs + Hocuspocus + Tiptap + Postgres

CRDT documents that merge concurrent edits

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