Free SQL-to-ER Diagram Tool Runs in the Browser and Uploads Nothing

A new free tool turns a SQL schema into a diagram without sending anything to a server. SQL to ER Diagram, published under the yourbrowsercandoit.com collection, takes CREATE TABLE statements or raw DDL and renders an interactive entity-relationship diagram in the browser.

Paste DDL, get a diagram

The workflow is deliberately small: paste schema definitions into the editor and the tool draws the tables, columns, primary keys, foreign keys and the relationships between them. It parses standard CREATE TABLE and ALTER TABLE DDL, including primary key, foreign key, unique and not-null constraints, and the project lists support for PostgreSQL, MySQL, MariaDB, SQLite, SQL Server, Oracle, Snowflake and BigQuery.

The tool is also positioned as a converter for schema languages beyond SQL: it reads Prisma schemas, DBML, Mermaid, SQLAlchemy and Sequelize models, and offers a separate guide for each dialect.

Editing, exporting, sharing

Once the diagram is on screen it stays editable. Tables can be dragged, the canvas zooms with the scroll wheel, double-clicking renames an element, and an auto-arrange option tidies the layout; notes can be added to the drawing as well.

Finished diagrams export as high-resolution PNG or vector SVG, and can also be written out as Mermaid, DBML or PlantUML. Beyond exports, the full project can be saved as a file, or shared as a link that encodes the diagram in the URL.

Local by design

The privacy claim is the pitch: everything runs in the browser, so the schema is never uploaded to or stored on a server, and there is no account or sign-up. Nothing has to be installed, and the site says it works on both desktop and mobile.

It is one of a collection of browser-only tools on yourbrowsercandoit.com. For teams that cannot paste a production schema into a hosted service, that constraint is the feature — the diagram is built, edited and exported on the machine it was pasted on.