BaseX vs JayDB

BaseX is a free, open-source XML database engine and XQuery processor for data-intensive web applications. It stores XML documents, binary data, and XQuery values, and handles XML, HTML, JSON, and CSV formats. Its XQuery 4.0 processor supports the W3C Update and Full Text extensions. You can operate it from the command line, in client/server mode, or through desktop and web interfaces. The graphical interface provides a query editor with syntax highlighting, keyword search, interactive visualizations, and server administration. RESTXQ supports building web applications with XQuery, while the server offers REST and WebDAV access to databases and resources. Concurrent reads, ACID-safe write transactions, user permissions, and secure authentication are supported. BaseX runs on Linux, macOS, and Windows, with API and self-hosted deployment listed. Java 17 or higher is required, and Adoptium distributions are recommended. The BaseX plan costs nothing.

JayDB is a JSON document database with per-user sign-in, aimed at static apps that need user, session, or tenant data without an app-owned backend. Documents are JSON at slash-separated paths, and the first write creates the namespace. Its REST data plane supports GET, PUT, DELETE, and prefix listing. Browser apps can authenticate through OIDC with Authorization Code and PKCE without embedding a client secret. Listed identity providers include Google, GitHub, Microsoft, generic OIDC, and custom OAuth2. The official SDK supports authentication, token refresh, typed document access, and compare-and-swap operations. ETag-based compare-and-swap may reject a write with HTTP 412 if the document changed since it was read. JayDB is available as managed cloud software or as a self-hosted Go engine under the MIT license, using S3-compatible storage or local disk. The free plan is free and includes 1 GB stored, 100,000 reads per month, and 10,000 writes per month; usage hard-stops at those allowances. Metered rates are $0.05 per GB-month of storage, $0.20 per million reads, and $0.50 per million writes.