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---
og_image: "/images/guides/tanstack-db-vs-zero-vs-livestore-sync-engines-2026.webp"
title: "TanStack DB vs Zero vs LiveStore: Reactive Sync Engines 2026"
description: "TanStack DB, Zero, and LiveStore compared for local-first sync: query model, conflicts, server requirements, and adoption maturity."
date: "2026-04-26"
author: "PkgPulse Team"
tags: ["tanstack-db", "zero", "livestore", "sync-engine", "local-first", "rocicorp", "2026"]
---

## TL;DR

**TanStack DB is the safest 2026 pick if you want incremental, reactive client-side queries that compose with TanStack Query and run anywhere — minimal server-side commitment. Zero (from Rocicorp, the Replicache successor) is the strongest end-to-end story when you can adopt their server protocol and a Postgres backend. LiveStore is the right call for event-sourced, log-driven apps where you want SQLite-on-the-client with a deterministic mutation log.** All three are part of the 2026 wave of "the client is no longer a dumb cache" — they treat your UI's data layer as a *real* reactive query engine, not a chain of `useEffect` hooks. Pick based on how much of your stack you're willing to rebuild around the sync engine.

## Quick Verdict

| | TanStack DB | Zero | LiveStore |
|---|---|---|---|
| Maker | TanStack | Rocicorp | Overtone (Schickling et al.) |
| Local store | In-memory + indexes | SQLite (Wasm/native) | SQLite (Wasm/native) |
| Query language | JS/TS query builder | ZQL (typed query DSL) | SQL + reactive views |
| Conflict resolution | Optimistic + server reconciliation | Server-authoritative + rebases | Event log (CRDT-like) |
| Server requirement | Any HTTP backend | Zero-cache server (Rocicorp) | Sync server (open source) |
| Backend coupling | Loose | Tight (Postgres + zero-cache) | Tight (event log) |
| Adoption stage | RC / 1.0 in 2026 | GA | Beta / 1.0 |

## Key Takeaways

- **The new bar is incremental queries.** All three deliver sub-millisecond reactive query updates by maintaining indexes/materialized views in the client, not by re-running queries against the network.
- **Server commitment is the deciding factor.** TanStack DB asks for the least; Zero asks for the most. Adopt Zero only when you're willing to put `zero-cache` in your stack as a real component.
- **CRDT vs server-authoritative is a real philosophical split.** LiveStore leans CRDT-like (event log, deterministic replay). Zero is server-authoritative (the server resolves; clients rebase). TanStack DB mostly delegates to your server's existing semantics.
- **TanStack Query is not going away.** TanStack DB layers *on top* of TanStack Query in many setups; if you already use TanStack Query, the migration cost is the lowest of the three.

## What Each One Actually Is

### TanStack DB

Technically a "reactive client store with incremental views". You define collections, write JS-style queries with joins/where/order, and the engine maintains those query results incrementally as mutations come in. It does *not* prescribe how data gets to the server — you wire it up to your existing API, GraphQL endpoint, or [tRPC v11](/guides/trpc-v11-vs-ts-rest-2026) procedures.

```ts
import { createCollection, createQuery } from "@tanstack/db";

const todos = createCollection<Todo>("todos", {
  queryFn: () => fetch("/api/todos").then(r => r.json()),
});

const openTodos = createQuery({
  from: todos,
  where: (t) => !t.completed,
  orderBy: (t) => t.createdAt,
});

// In a React component, openTodos.subscribe() updates incrementally
```

The selling point is "I want my UI to feel local-first, but I don't want to throw out my REST API." It pairs naturally with TanStack Query for transport and cache invalidation.

### Zero

Rocicorp's successor to Replicache. The bet is bigger: Zero ships its own query language (ZQL), its own server (`zero-cache`), and its own protocol. In return you get true sync semantics — a permission model that runs on the server, end-to-end query subscriptions, and rebase-on-conflict handling.

```ts
import { Zero } from "@rocicorp/zero";

const z = new Zero({
  userID: "user-42",
  server: "https://zero.example.com",
  schema, // generated from Postgres
});

const issues = z.query.issue
  .where("assigneeId", "=", "user-42")
  .orderBy("createdAt", "desc")
  .limit(50);

// `issues` is reactive — subscribe in React via useQuery(issues)
```

Zero is the most complete answer here, but you commit to Postgres, the zero-cache server, and Rocicorp's hosted or self-hosted infrastructure.

### LiveStore

Built around an event-sourced model: every mutation is an event appended to a log; the client materializes views (SQLite tables) by replaying the log; the server is itself a log replicator. This makes time-travel, undo, and offline merging cleaner than a traditional CRUD model.

```ts
import { makeStore, defineEvents, sql } from "@livestore/livestore";

const events = defineEvents({
  todoCreated: { schema: { id: "string", text: "string" } },
  todoCompleted: { schema: { id: "string" } },
});

const store = await makeStore({
  events,
  materializers: {
    todoCreated: ({ id, text }) =>
      sql`INSERT INTO todos (id, text, completed) VALUES (${id}, ${text}, 0)`,
    todoCompleted: ({ id }) =>
      sql`UPDATE todos SET completed = 1 WHERE id = ${id}`,
  },
});

await store.commit(events.todoCreated({ id: "t1", text: "buy milk" }));
const open = await store.query(sql`SELECT * FROM todos WHERE completed = 0`);
```

You write SQL (or use the typed builder) against a real SQLite database that lives in the user's browser via `sqlite-wasm`. The mutation log is the source of truth; the table is a view.

## Decision Map

| If you... | Pick |
|---|---|
| Already use TanStack Query and want incremental views | **TanStack DB** |
| Want the most complete sync story and can adopt zero-cache | **Zero** |
| Need event-sourced semantics or time-travel | **LiveStore** |
| Have an existing REST API you can't rewrite | **TanStack DB** |
| Are starting greenfield with Postgres | **Zero** |
| Need offline-first with deterministic merge | **LiveStore** |
| Need a hosted, "just works" sync provider today | [Convex / InstantDB / ElectricSQL](/guides/convex-vs-instantdb-vs-electricsql-real-time-sync-2026) |

## Server Requirements: The Real Cost

This is where most architecture decisions land:

| | TanStack DB | Zero | LiveStore |
|---|---|---|---|
| Add a new server? | No (use yours) | Yes (`zero-cache`) | Yes (sync server) |
| Backend protocol | Whatever you have | Zero-specific | LiveStore-specific |
| Permission layer | In your existing API | In `zero-cache` config | In materializer / replication |
| Postgres required | No | Effectively yes | No |

Zero's `zero-cache` is the most opinionated component. You run it next to your Postgres, it tails replication, and it serves filtered query subscriptions to clients. This is power *and* operational complexity.

## Conflict Resolution Models

- **TanStack DB**: optimistic mutations + server reconciliation. If the server rejects, your client rolls back. Simple, but means the *server* is still the source of truth for conflicts.
- **Zero**: server-authoritative with client-side rebase. Clients optimistically apply, the server resolves, the client rebases on top of the canonical history. Closer to git semantics.
- **LiveStore**: event-sourced. Conflicts are resolved by event ordering rules and materializer determinism. The mental model is closer to CRDTs without committing to a CRDT library.

For broader local-first context (and database engines that pair with these), see [PGlite vs ElectricSQL vs Triplit](/guides/pglite-vs-electric-sql-vs-triplit-local-first-databases-2026).

## Who Should Pick What

- **Existing React app with TanStack Query**: TanStack DB. The migration is incremental and your server stack is untouched.
- **Greenfield collaborative app, Postgres-backed**: Zero. The protocol/server cost is real but the result is the slickest sync story available in 2026.
- **Event-sourced app or one that needs replay/audit semantics**: LiveStore. Don't try to retrofit event sourcing onto TanStack DB; you'll fight the model.
- **Production-critical data-sync need today**: a hosted option (Convex, InstantDB) is still the safer pick for non-experimental teams in early 2026.

## Verdict

TanStack DB is the lowest-risk 2026 entry into incremental client-side queries — no new server, no new protocol. Zero is the most ambitious and the most complete; treat it as a multi-quarter platform commitment. LiveStore is a niche-but-deep choice for event-sourced apps. The category is moving fast: re-evaluate before any greenfield commitment because GA timelines and hosted offerings continue to shift through 2026.

## Related Reading

- [Convex vs InstantDB vs ElectricSQL](/guides/convex-vs-instantdb-vs-electricsql-real-time-sync-2026)
- [PGlite vs ElectricSQL vs Triplit](/guides/pglite-vs-electric-sql-vs-triplit-local-first-databases-2026)
- [TanStack Query v5 vs SWR v3 vs RTK Query](/guides/tanstack-query-v5-vs-swr-v3-vs-rtk-query-data-fetching-2026)
- [Yjs vs Automerge vs Loro CRDTs](/guides/yjs-vs-automerge-vs-loro-crdt-libraries-2026)