[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Platform](https://evolu.dev/docs/api-reference/common/Platform) › isDev

```ts
const isDev: boolean;
```

Defined in: [packages/common/src/Platform.ts:24](https://github.com/evoluhq/evolu/blob/037c390af081e9944d616ff298a729515c5c5ab7/packages/common/src/Platform.ts#L24)

True outside production builds.

Bundlers (webpack, Vite, esbuild, Metro) replace the text
`process.env.NODE_ENV` statically at build time, so in production bundles
this expression folds to `false` and code behind it is dead-code-eliminated —
the same mechanism React uses. The `typeof` guard makes the runtime read safe
where no bundler ran, such as un-bundled browser ESM, where it fails closed
to production behavior. Node.js reads it natively; React Native polyfills it.
A missing `NODE_ENV` counts as development, matching React semantics.