[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [local‑first/Evolu](https://evolu.dev/docs/api-reference/common/local-first/Evolu) › DevicePersistence

```ts
type DevicePersistence = "Persisted" | "NotPersisted" | "Unknown";
```

Defined in: [packages/common/src/local-first/Evolu.ts:950](https://github.com/evoluhq/evolu/blob/bb2644275dd99ff6dce4744db578967699045ea3/packages/common/src/local-first/Evolu.ts#L950)

Whether this device keeps an [Evolu](https://evolu.dev/docs/api-reference/common/local-first/Evolu/interfaces/Evolu) database, stating only what Evolu
knows for sure.

- `Persisted`: the platform stores it in the app's own file, as React Native
  does.
- `NotPersisted`: it is kept in memory, because [EvoluConfig.memoryOnly](https://evolu.dev/docs/api-reference/common/local-first/Evolu/interfaces/EvoluConfig#memoryonly)
  asks for that or the platform offers no persistent storage, as a browser
  does in Safari's Private Browsing or a Firefox private window. Data that
  has not synced is lost when the database closes.
- `Unknown`: it is stored, but the platform may delete it. A browser can keep
  storage only for a private session, as Chrome's incognito does without
  telling the app, delete it after a while or when disk space runs low, and
  let the user clear it.

See [Will my data stay on the
device?](https://www.evolu.dev/docs/faq#will-my-data-stay-on-the-device).