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ER Diagram Generator

Describe your database schema in plain text — define entities, fields, types, and relationships — and instantly get a professional, industry-grade entity-relationship diagram. Export as SVG or PNG.

📝 Schema Definition Plain text → diagram

Templates:

⚠️ Parse Error

📖 Syntax Reference

# Define an entity (table) entity EntityName { PK id INT field_name VARCHAR(100) created_at DATETIME FK other_id INT } # Define relationships relation EntityA to EntityB { type: one-to-many label: "has many" } # Supported types: # one-to-one | one-to-many # many-to-many | many-to-one

PK = Primary Key · FK = Foreign Key · UK = Unique Key
Fields without a prefix are regular columns. All field names support spaces if quoted.

🗄️

No diagram yet

Write your schema on the left and click "Generate ER Diagram"

What is an ER Diagram?

An Entity-Relationship (ER) diagram is a visual blueprint of a database. It shows the entities (tables), their attributes (columns), and the relationships between them. ER diagrams are used by database architects, backend developers, and software teams during the design phase to plan and communicate database structure before writing any code.

How to use this tool

Define each table using the entity keyword followed by a name and curly braces
Inside each entity, list fields with an optional prefix: PK for primary key, FK for foreign key, UK for unique key
After the field name, specify the SQL data type (INT, VARCHAR, DATETIME, etc.)
Define relationships using the relation keyword with one-to-one, one-to-many, or many-to-many
Use the template buttons to load a full working example and customise from there

Yes — use the SVG button to download a scalable vector file (perfect for documentation and presentations), or PNG for a raster image suitable for embedding in reports. Both export options are in the toolbar above the diagram.

The tool supports all four standard crow's foot notation relationship types: one-to-one, one-to-many, many-to-one, and many-to-many. Each is rendered with the correct crow's foot symbols on the relationship lines.

No. The entire tool runs client-side in your browser — nothing is sent to any server. Your schema text stays entirely on your machine.

Any SQL data type works as a label — INT, BIGINT, VARCHAR(n), TEXT, BOOLEAN, DECIMAL, FLOAT, DATE, DATETIME, TIMESTAMP, JSON, UUID, and so on. The tool treats the type as a display string, so you can write any type you use in your actual database.

Done!

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Frequently Asked Questions

Is this ER Diagram Generator free to use? +

Yes, completely free. No signup, no account, no payment required. Just paste your input and use it directly in your browser.

Does this tool store or send my data anywhere? +

No. Everything runs entirely in your browser using JavaScript. Your data never leaves your device or gets sent to any server.

What browsers does this tool support? +

It works in all modern browsers — Chrome, Firefox, Safari, Edge, and Opera — on both desktop and mobile.

Can I use this tool offline? +

Once the page is loaded, the tool runs locally in your browser without needing an active internet connection for most operations.