Getting started

EntityModel.com runs at entitymodel.com with nothing to install. This page walks through a first model, then explains how to run it on your own machine.

#Make your first model

1. Open entitymodel.com. The home page lists your models. On a first visit it is empty.
2. Look at the demo (optional). Click Open the demo to copy a supplier model with reference lists, relationships and a hierarchy into your browser. It's a quick way to see every feature.
3. Click New model. Give it a title and, optionally, an organization. The diagram canvas opens.
4. Add entities. Press E or use the toolbar to add an entity, such as customer. In the inspector on the right, add attributes with their data types, and mark one as the primary key.
5. Paste attributes in bulk. Paste a CREATE TABLE statement, name TYPE lines or spreadsheet columns into the attributes list to add many at once.
6. Draw relationships. Press R for the relationship tool and drag from one entity to another. Set the cardinality (1:1, 1:N, N:1 or N:N) and the forward and reverse labels, such as "Customer places Order".
7. Check the Issues panel. Validation runs as you edit. Click an issue to jump to it.
8. Export. Click Export for a PNG or SVG diagram, a PDF design document, SQL DDL or the model file itself.

Your work saves automatically in the browser. Press ⌘S (or Ctrl+S) at any time to save immediately.

Browser storage is private to one browser profile, and clearing site data deletes it. Export the model file (Export → Model file) for anything you want to keep.

#Start from something you already have

• SQL or DBML. Click Import SQL or DBML on the home page and paste or drop CREATE TABLE scripts or a dbdiagram.io file. See SQL to ER diagram.
• A live database. Use Import → From a database to build a metadata query for Databricks, Snowflake, PostgreSQL or MySQL, run it in your own SQL tool, and paste the result. See Import from a database.
• An example. Open one of the example data models (e-commerce, CRM, HR and more) and adapt it.
• A model file. Click Open model file, or drop a .json model anywhere on the home page.
• A description. Design with Claude copies a ready-made prompt you can paste into Claude, then paste the model it writes back in. See AI data modeling.

#Find your way around

• Canvas. Drag empty space to box-select; Space+drag, middle-drag or a two-finger scroll pans. Right-click a selection for Hide, Show only these, Arrange, Color, Copy to tab and more.
• Detail level. The toolbar toggle switches entity cards between All attributes, Keys only and Names only.
• Inspector. Select anything to edit it: entities, attributes, relationships, hierarchies, subject areas, notes and the model itself.
• Command palette. Press ⌘K to jump to any entity, attribute (order.status), relationship or tab, or to run any action.
• Tabs. One model can hold several diagrams, such as a conceptual, a logical and a physical view. See Derive, compare and migrate tabs.

All shortcuts are listed in Keyboard shortcuts.

#Run it locally

Running locally keeps each model as a JSON file on disk, which lets you version models in Git and use the CLI and AI agents. You need Node.js 18 or later.

git clone https://github.com/ns-3e/entitymodeler.git
cd entitymodeler
npm install
npm run dev          # opens http://localhost:5180

The app chooses where to store models by itself:

Add ?storage=browser to the URL to force browser storage when running locally.

#Next steps

• Core concepts: entities, reference entities, structs, relationships and hierarchies.
• Export SQL DDL for your database.
• What is an ER diagram? if you're new to data modeling.