Last year I posted on some Data Modeling Tools that I had looked at. I’ve recently checked out ERD Lab.
ERD Lab is browser-based, and allows sharing with up to 5 users, with either read-only or read/write permissions.
The tool supports MySQL, SQL Server, SQLite, Postgres, Oracle, and Snowflake. You can also create a model without a database type specified, to create a vendor-neutral model. You can import a DDL script to create a model, and you can export to PNG, PDF, or export to a SQL build script.
With the table columns, you can specify data type, primary keys, nullability, add a unique constraint for the column, as well as define foreign keys.
A user can add notes for a table, as well as adding notes on the display itself. There’s also a model history available, in case a change needs to be reverted.
There are a few unique features I liked. You can create multiple tabs in the tool to have multiple models open. I also like the support page, it uses animated GIFs to show you how to perform certain tasks. They also provide some templates for models to use as a starting point.
There’s a graphical editor, as well as a markup pane that allows you to create objects using code. Here’s an example: 

customer {
	customer_id integer pk increments
	first_name string
	last_name string
}

Changes to the markup are reflected in real time in the graphical layout. I really liked this functionality, once I got the hang of the format I found it easier to create the model with this markup.
The tool is free to use, which is pretty incredible. You can login as a guest to try it out, or create a free account to save your own models.
If you need a data modeling tool, I would definitely recommend ERD Lab