SQL Server to ER Diagram

How it works

1. Script the schema from SSMS (right-click the database → Tasks → Generate Scripts), or copy your CREATE TABLE statements.
2. Paste it into the editor — T-SQL is parsed automatically.
3. Tables render with columns; FOREIGN KEY constraints become relations.
4. Arrange, hide tables, then export PNG/SVG or share a link.

Example

A T-SQL schema like this:

CREATE TABLE customers (
  id INT IDENTITY(1,1) PRIMARY KEY,
  email NVARCHAR(255) NOT NULL UNIQUE
);

CREATE TABLE orders (
  id INT IDENTITY(1,1) PRIMARY KEY,
  customer_id INT NOT NULL,
  CONSTRAINT FK_orders_customers
    FOREIGN KEY (customer_id) REFERENCES customers(id)
);

…renders two tables with a relation from orders.customer_id → customers.id. Try it with your own →

Guide

The fastest path from SQL Server to a diagram: in SSMS, right-click the database → Tasks → Generate Scripts, choose the tables you want, and on the Scripting Options page set Script Data = False and Script Indexes = False (indexes just add noise). Paste the resulting file. The parser handles everything T-SQL-specific about that output: [dbo].[customers] bracket-quoting, IDENTITY(1,1), NVARCHAR(MAX), named CONSTRAINT FK_… blocks, and the GO batch separators.

If you prefer a query over a wizard, script the DDL yourself:

SELECT OBJECT_DEFINITION(f.object_id) FROM sys.foreign_keys f;

— or just paste your hand-written CREATE TABLE scripts; nothing needs to be pretty. Azure SQL Database and Synapse output works the same way. One tip: generate only the tables you actually want on the diagram. A 400-table ERP paste renders, but a 30-table slice of the sales schema is far more useful in a design review.

Why use it

• Private: everything runs in your browser — nothing is uploaded or stored on a server.
• Interactive: drag tables, auto-arrange, hide noise, add notes, and manually link columns.
• Export a high-res PNG, vector SVG, or the schema as Mermaid / DBML / PlantUML code.
• Handles named constraints like CONSTRAINT FK_… FOREIGN KEY.
• Free & open source — no account, no sign-up.

FAQ

How do I create an ER diagram from SQL Server?

In SSMS use Tasks → Generate Scripts to script the schema, then paste it here. Tables and foreign-key constraints are drawn automatically.

Is my schema uploaded anywhere?

No. Everything runs locally in your browser — your schema is never uploaded to or stored on any server.

Can I export the diagram?

Yes — export a high-resolution PNG or vector SVG, copy the schema as Mermaid, DBML or PlantUML, or share a link that encodes the whole diagram in the URL.

Is it free?

Yes. It is completely free and open source, with no account or sign-up required.

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