ERoo - A free ER diagram creation tool usable in your browser

ERoo is a free ER diagram creation tool that works in a web browser only. No installation is required—simply open the site and you can start designing databases right away.

When creating tables (entities), you can configure not only columns and data types, but also primary keys, indexes, constraints, comments, and tags in detail. A distinctive feature is the ability to register views by writing SELECT statements. Relationships between tables can specify multiplicity and foreign key constraints.

Additionally, it supports DDL import to automatically generate ER diagrams from existing CREATE statements, and DDL export to write out your design as SQL. This seamlessly connects design, implementation, and documentation. The ER diagrams you create can be saved to your PC (locally) or Google Drive, allowing you to continue editing from another device.

The appeal is that whenever you think "I want to quickly sketch an ER diagram," you can use it without any environment setup. From learning purposes to team-based practical work, this completely free design tool can be utilized across a wide range of applications.