Free ER Diagram Generator

An entity relationship diagram, also called an ER diagram or ERD, is a visual model of a data system that shows the entities (tables or objects), their attributes (columns or properties), primary and foreign keys, and the relationships between entities including cardinality (how many records in one entity relate to how many in another). ER diagrams are the standard schema documentation figure in database and information systems research. SciFig's ER diagram generator produces labeled ERDs from a plain-language description of your data model.

ER diagram and ERD are two names for the same thing — entity relationship diagram. Both terms describe the visual schema model that maps entities, attributes, and relationships in a relational database. You may also encounter the term entity-relationship model. SciFig's ERD diagram maker accepts descriptions in any terminology and generates a consistent, labeled figure using your preferred notation style.

Chen notation represents entities as rectangles, attributes as ovals connected by lines, and relationships as diamonds with cardinality labels. Crow's Foot notation uses lines ending in symbols resembling crow's feet, rings, and bars to encode cardinality and participation directly on the relationship line — making it more compact and widely used in software engineering and ERD diagram maker tools. SciFig's ER diagram generator can apply either notation style based on your description.

In a many-to-many relationship, each record in entity A can relate to multiple records in entity B and vice versa. In an ER diagram this is typically shown with Crow's Foot symbols at both ends of the relationship line, or a diamond labeled 'M:N' in Chen notation. For relational databases, many-to-many relationships are often resolved into a junction table. Describe the relationship in plain language and SciFig's ER diagram generator AI will model it correctly with the appropriate cardinality notation.

Yes. SciFig's er diagram generator AI interprets natural-language descriptions of data models — for example, 'a Patient entity with PatientID (PK), name, and date of birth; an Appointment entity with AppointmentID (PK), date, and a foreign key to Patient and Doctor' — and generates a clean, labeled ERD with the correct cardinality and key notation. You can use the er diagram online result as-is or edit it before exporting.

ER diagrams are used wherever structured data storage is designed or documented: database research, information systems, bioinformatics (genomic and clinical data schemas), health informatics, software engineering, data science, and computational social science. Any research paper describing a custom database or data collection system should include an ER diagram in its methods section — a figure SciFig's ERD maker produces at publication quality.