Choose Storage
Pick the right Expo storage primitive.
Decision tree
- Tokens, passwords, API keys → expo-secure-store (Keychain on iOS)
- Tiny preferences (<10 keys) → AsyncStorage or Zustand persist
- Fast key/value (>10 keys, frequent reads) → MMKV (
react-native-mmkv) - Structured data, complex queries → expo-sqlite + drizzle-orm
- Large blobs / images → expo-file-system
- Cross-device sync → CloudKit private DB (requires native bridge or expo-cloud-storage if available)
expo-secure-store
tsimport * as SecureStore from 'expo-secure-store'; await SecureStore.setItemAsync('authToken', token); const token = await SecureStore.getItemAsync('authToken');
MMKV
bashnpm install react-native-mmkv
tsimport { MMKV } from 'react-native-mmkv'; export const storage = new MMKV(); storage.set('user.id', '123'); const id = storage.getString('user.id');
~30x faster than AsyncStorage. Sync API.
expo-sqlite + drizzle
bashnpm exec --no -- expo install expo-sqlite npm install drizzle-orm npm install -D drizzle-kit
tsimport { drizzle } from 'drizzle-orm/expo-sqlite'; import * as SQLite from 'expo-sqlite'; const sqlite = SQLite.openDatabaseSync('app.db'); export const db = drizzle(sqlite);
ABSOLUTE NO
- Never store auth tokens in AsyncStorage or MMKV (no encryption at rest)
- Never put images in expo-sqlite (use expo-file-system)
- Don't pick CoreData via native bridge unless you specifically need NSPersistentCloudKitContainer features


