ERoo - A free ER diagram creation tool that works in your browser

ERoo is a free ER diagram creation tool that works only in a web browser. No installation is required at all—you can start database design immediately by opening the site.

When creating tables (entities), you can configure columns and data types in detail, as well as primary keys, indexes, constraints, comments, and tags. A distinctive feature is the ability to register views (VIEW) by writing SELECT statements, and 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 the designed content as SQL. This seamlessly connects design, implementation, and documentation. The created ER diagrams can be saved to your PC (locally) or Google Drive, allowing you to continue editing from another device.

The appeal is that you can use it without any environment setup the moment you think "I want to quickly draw an ER diagram." From learning purposes to team-based practical work, it's a completely free design tool that can be used widely.