DuckDB UI vs ObjectBox

DuckDB UI is a free browser interface for a local DuckDB instance, added through the ui extension. Start it with `duckdb -ui` or `CALL start_ui()`; it opens in the default browser and is served by an HTTP server embedded in DuckDB, available by default at `http://localhost:4213`. The interface includes a SQL notebook with autocomplete and keyboard shortcuts, a catalog browser, a table explorer with column statistics, and a results viewer with sorting and filtering. The native DuckDB process gives it access to local cores, memory, and files. Queries run locally by default, and queries and data stay on the computer. Connecting to MotherDuck is optional and requires signing in. The UI is built and maintained by MotherDuck. The local server retrieves interface files from ui.duckdb.org, so alternate configured URLs should be trusted because the application can access loaded DuckDB data. The UI cannot be run directly against a read-only database and does not currently support windows_arm64.

ObjectBox is an embedded, object-oriented NoSQL database for mobile applications and IoT devices. Its database provides native object APIs, relationships, reactive observers, ACID transactions and automatic schema migration. ObjectBox Sync can move data between devices and a backend or server, including for offline-first use cases. Listed language APIs include Java, Kotlin, Swift, Flutter/Dart, Go, Python and C/C++. The product supports vector search, with no embedding-column dimension limit stated in its FAQ. ObjectBox says it supports direct synchronization to MongoDB; connectors for other backend databases may require custom development. Its Sync Server can be self-hosted on POSIX systems and cloud providers, though ObjectBox does not currently provide cloud hosting. The core database plan is free; Sync pricing is quoted per project based on needs. The company describes its focus as mobile and IoT development, particularly decentralized systems with restricted devices and offline scenarios. Mesh Sync is available for Android Java/Kotlin and Flutter/Dart starting with version 6.0.0-beta, with APIs that may change before final release.