expo-file-system — Local file management

A comprehensive API for reading, writing, and managing local files and directories across Android, iOS, and web platforms.

Manage local storage with precision using the FileSystem API. This library handles essential tasks: reading and writing strings or base64 data, moving files between the documentDirectory and cacheDirectory, and performing SHA-256 integrity checks. It excels at heavy lifting (like background downloads via createDownloadResumable) and provides real-time progress callbacks for large assets. Use it to store SQLite databases, cache media for offline use, or organize app-specific metadata without the overhead of manual native bridging.

https://docs.expo.dev/versions/latest/sdk/file-system/