An ER diagram maker that speaks SQL
DesignDB draws an entity relationship diagram the way a database sees it: tables with typed columns, primary and foreign keys, indexes and constraints, rather than loose boxes and arrows. Because the model is a real schema, the same diagram can later become SQL, an ORM schema or a migration.
What you can draw
- Tables and columns with the types of the database you choose: PostgreSQL, MySQL, MariaDB, SQLite or SQL Server.
- Primary keys, unique and check constraints, defaults, indexes and generated columns.
- Relationships drawn as foreign keys, with the cardinality shown (one to one, one to many, many to many).
- Areas to group related tables, and notes to explain a decision.
- Views, enums and custom types where the database has them.
Start from a schema, not a blank page
Every template opens as an ordinary diagram you can reshape: add a column, rename a table, split an entity in two. The templates below show common shapes (multi-tenant SaaS, a shop, a blog, bookings) with sensible keys and constraints.
Works alone, grows into a team tool
Try it in your browser with no account: your diagrams stay in that browser. A free account saves up to 5 diagrams in the cloud, with up to 50 tables each. Importing and exporting SQL and other formats, sharing, comments and version history are part of Pro.
Schemas to start from
Questions
Is the ER diagram maker free?
Yes for drawing: the editor works in your browser without an account. A free account adds cloud saving for up to 5 diagrams. Import, export, sharing and live collaboration are part of the paid plans.
Which databases does it support?
PostgreSQL, MySQL, MariaDB, SQLite and SQL Server for ordinary schemas, and Snowflake, BigQuery and Redshift on the Team plan.
Can I convert a diagram between databases?
Yes. Switching the database converts types and features and tells you exactly what changed or could not be carried over.