Free ER diagram tool?

Looking for a free ER diagram tool? There are many on the market and Moon Modeler is one of them.
This free ER diagram tool can be used to visually define smaller database structures for relational database systems such as MariaDB, MySQL, PostgreSQL, SQLite, and NoSQL databases such as MongoDB, or object-document mappers such as Mongoose.

Moon Modeler can be installed as a trial version, which automatically switches to freeware mode when the trial expires.

An example of a sample ER diagram created for the target MariaDB platform:

Free database modeling tool

Trial version

All key features are enabled in the trial version and you can try the fully functional software for 14 days. After that, the software expires and the following modal form is displayed:

Database modeling tool and freeware mode switch

As you can see, you can purchase the commercial version by clicking on the Buy Now button and following the instructions, activate the already purchased product or continue with the freeware version of the database modeling tool

Click Continue with freeware to enable the freeware mode.

Limitations of the free ER diagram tool

Maximum 10 tables/collections in a project
Freeware version does not include reverse engineering features
Import from GraphQL and SQLite is not available
Watermark in exported PDF file

In freeware mode, you can create smaller projects with up to 10 objects.
You can add more objects to the project, but saving the project will not be allowed.

If you add more than 10 objects to a project or try to save a larger project (opened from a file system, for example), the following notification will appear in the program:

Freeware mode and notifications

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