- Free ER diagram tools compared
- draw.io: the general-purpose free choice
- dbdiagram: design your schema as code
- pgAdmin ERD Tool: free for PostgreSQL users
- DBeaver Community: map an existing database
- ChartDB: open source and AI-assisted
- Lucidchart free plan: fine for a one-off
- Which free ER diagram tool should you use?
- My verdict on free ER diagram tools
- Frequently asked questions
The best free ER diagram tools are draw.io for general diagrams, dbdiagram for writing schemas as code, pgAdmin's ERD Tool for PostgreSQL, DBeaver Community for reverse-engineering an existing database, ChartDB for open source schema diagrams, and Lucidchart's free plan for quick sketches. Which is best depends on whether you're designing from scratch or mapping a live database.
An entity relationship diagram shows your tables, their columns and how they connect. Some free tools only draw the boxes; others generate SQL or read your real database. Here's what each one's own site says, checked as of October 2026.
Free ER diagram tools compared
| Tool | What's free | Generates SQL? | Reads a live database? |
|---|---|---|---|
| draw.io | Free, Apache 2.0 licensed source code | No, but it builds tables from your SQL | No |
| dbdiagram | Free plan up to 10 diagrams and doc projects | Yes, export schema as SQL | No |
| pgAdmin ERD Tool | Free, released under the PostgreSQL licence | Yes, ready-to-run SQL | Yes, for PostgreSQL |
| DBeaver Community | Free, open source | Not the focus | Yes, diagrams for existing tables and schemas |
| ChartDB | Free and open source, can be self-hosted | Yes, DDL scripts | Yes, keeps in sync with your database |
| Lucidchart | Free plan: 3 editable documents | No | No |
draw.io: the general-purpose free choice
draw.io is a free diagramming tool whose site highlights Apache 2.0 licensed source code and the option to store your data wherever you want. Its documentation says ER diagrams have their own shape library: click More shapes at the bottom of the left panel, select Entity Relation in the Software section and click Apply.
The feature most people miss is SQL import. draw.io's docs say you can document an existing database by going to Arrange, Insert, Advanced, SQL and pasting your SQL code. It adds table shapes with rows for each attribute, and you then connect the relationships yourself. It won't write SQL back out or connect to a live database, so it's best when the diagram is the deliverable.
dbdiagram: design your schema as code
dbdiagram lets you describe tables in a simple text language and draws the diagram for you. Its pricing page says the free plan is for individuals designing schemas and sharing public docs, with up to 10 diagrams and doc projects, one view per diagram, view-only link sharing and one embed. You can export your schema as SQL scripts and your diagrams as SVG, PDF or PNG. Students, teachers and researchers get Personal Pro free for 12 months, renewable while they're at an institution.
pgAdmin ERD Tool: free for PostgreSQL users
If your database is PostgreSQL, you may already have this. pgAdmin's documentation says the ERD Tool lets you design and visualise tables and relationships, auto-align them, generate ready-to-run SQL from the design, and generate the diagram for an existing database. pgAdmin's licence page says pgAdmin 4 is released under the PostgreSQL licence, which permits use for any purpose without fee.
DBeaver Community: map an existing database
DBeaver Community describes itself as a free, open source database management tool for SQL databases such as MySQL, MariaDB, PostgreSQL and SQLite. Its documentation says you can open diagrams for individual tables and views or for full schemas, rearrange entities and relationships, and export diagrams. It's the one I'd pick when you've inherited a database and need to see what's in it.
ChartDB: open source and AI-assisted
ChartDB calls itself a free and open source database design editor that you can self-host. It imports a schema, lets you edit the diagram and exports DDL scripts in your SQL dialect or an image. It supports MySQL, MariaDB, PostgreSQL, Microsoft SQL Server and SQLite, and its AI generator turns database ideas into editable ER diagrams.
Lucidchart free plan: fine for a one-off
Lucidchart's pricing FAQ says its free version includes three editable documents, up to 75 shapes per document and 100 professional templates. That's enough for one or two small ERDs, but a real schema can hit the shape cap fast. The free trial of its paid plans lasts seven days.
Which free ER diagram tool should you use?
- Drawing a diagram for a document or presentation: draw.io.
- Designing a new schema and wanting SQL out of it: dbdiagram or ChartDB.
- Working on PostgreSQL every day: pgAdmin's ERD Tool, since it's already in the toolbox.
- Understanding a database someone else built: DBeaver Community or ChartDB, which read the live structure.
- Sharing a quick sketch with a non-technical colleague: Lucidchart's free plan.
A quick word on cost creep: the free plans above are fine for one project, but dbdiagram caps you at 10 diagrams and Lucidchart at three documents. If you document databases for clients, the open source options you install yourself, such as draw.io, pgAdmin and DBeaver Community, don't list diagram caps like these.
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Whichever you pick, keep the diagram next to the database. The most common ERD failure isn't the tool, it's a diagram nobody updated after the third schema change.
My verdict on free ER diagram tools
If I could only install one, it'd be DBeaver Community, because reading the real database beats drawing what you think is there. For designing from scratch, dbdiagram's text approach is the fastest. For broader diagramming beyond databases, see my guide to free diagram software, the draw.io alternatives and my take on whether draw.io is free.
Frequently asked questions
What is the best free ER diagram tool?
It depends on the job: draw.io for general diagrams, dbdiagram for schema-as-code, pgAdmin's ERD Tool for PostgreSQL, DBeaver Community or ChartDB for mapping an existing database.
Can a free tool generate an ER diagram from my database?
Yes. pgAdmin's ERD Tool can generate the diagram for an existing PostgreSQL database, DBeaver Community opens diagrams for existing schemas, and ChartDB keeps a diagram in sync with your live database.
Is dbdiagram free?
Yes, for up to 10 diagrams and doc projects on the free plan, with SQL and image export. Students, teachers and researchers get Personal Pro free for 12 months.
Can I make an ER diagram in draw.io?
Yes. draw.io has an Entity Relation shape library, and its Arrange, Insert, Advanced, SQL option builds table shapes from your SQL code. You connect the relationships yourself.
Is pgAdmin free for commercial use?
pgAdmin's licence page says pgAdmin 4 is released under the PostgreSQL licence, which grants permission to use it for any purpose without fee.
How many diagrams does Lucidchart's free plan allow?
Lucidchart's free version includes three editable documents with up to 75 shapes per document.
