# Performance

> **Continuously verified**
>
>
> These benchmarks run on every commit. If a regression is detected, the PR is blocked until performance is restored.

Benchmarks: [https://valdres.dev/guides/performance](https://valdres.dev/guides/performance)

## Why the core is fast

The engine is optimized for minimal allocations and cache-friendly data structures — WeakMap-based storage with no intermediate objects, and transactions that batch updates so subscribers fire once.

In **React** specifically, the adapter is built on `useSyncExternalStore` (where Jotai uses `useEffect` + `useReducer`), which avoids extra renders and effect-cleanup overhead. The other adapters integrate with each framework's native reactivity — Vue refs, Svelte runes, Solid signals, Angular signals — so there the relevant performance is the framework's own.

> **What these numbers are (and aren't)**
>
>
> Every benchmark here compares the core Valdres engine against Jotai at the JavaScript level. They are not framework-rendering benchmarks, and Valdres does not claim to be faster than a framework's native reactivity (e.g. Svelte runes). The adapters exist to share one store across frameworks, not to outrun them.

## Running benchmarks locally

```bash
# Bun (JSC/Safari engine)
bun run --cwd packages/valdres test:bench

# Node.js (V8/Chrome engine)
bun run --cwd packages/valdres test:bench:node
```

## Historical trends

Performance is tracked over time on every push to `main`. View the live, always-current numbers and history at [bencher.dev/perf/valdres](https://bencher.dev/perf/valdres).