A free, open-source tool called SQL to ER Diagram converts database schemas into interactive entity-relationship diagrams directly in your web browser. Developers can paste CREATE TABLE statements and instantly visualize tables, columns, primary keys, and foreign key relationships without any installation or account setup.

The tool supports multiple database dialects including PostgreSQL, MySQL, SQLite and SQL Server, parsing standard CREATE TABLE and ALTER TABLE DDL statements. It handles primary keys, foreign keys, unique constraints, and not-null specifications, making it broadly compatible with common database schemas.

All processing happens client-side with no server uploads, ensuring complete data privacy. Users can drag tables to rearrange layouts, add notes, and export diagrams as high-resolution PNG or SVG files. The tool also offers project saving and shareable links that encode diagram data directly in the URL.

For developers working with database design or documentation, this eliminates the friction of desktop ERD tools while maintaining privacy. The browser-based approach means immediate access across devices without the overhead of traditional database modeling software.