The best free ER diagram tools, compared
Five tools that can draw an ER diagram without costing you anything, judged on four facts: what input they take, where the free tier stops, who sees your schema, and what you can export. Disclosure: we make one of them.
What we compared
- Input — can it read the SQL you already have, or does your schema have to be rebuilt in its own format first?
- Free limit — tables per diagram, diagrams per account, or nothing at all.
- Privacy — whether the schema is stored on someone's server, and who can see it.
- Export — an image is the baseline; text formats (SQL, Mermaid) keep the diagram diffable.
Five tools, one grid
| Input | Free tier | Privacy | Export | |
|---|---|---|---|---|
| ERD Tools | Real SQL, as written — PostgreSQL, MySQL, SQLite, SQL Server, BigQuery, Snowflake, mysqldump | Unlimited diagrams, 50 tables each, no account | Nothing stored | SVG · PNG · Mermaid |
| dbdiagram.io | DBML, its own notation — SQL imports are converted into DBML | 10 diagrams; private mode free since Oct 2026 | Saved in your dbdiagram workspace | SQL · images · share links |
| drawDB | Visual editor, with SQL import and export | No table cap — open source, runs in your browser | Client-side; self-hostable (AGPL-3.0) | Images · SQL scripts |
| DrawSQL | Visual editor, tables and relations drawn by hand | 15 tables per diagram, public | Free diagrams are public; private is paid | Images · SQL |
| QuickDBD | Its own shorthand syntax, typed live | 1 public diagram, 10 tables | Free diagram is public | Images |
Third-party facts checked against each vendor's official site in November 2026 — plans change, so follow the links for current numbers.
Who each one is for
ERD Tools
Paste DDL — including raw pg_dump and mysqldump files with all their noise — and the diagram renders in your browser. 50 tables per diagram free, no account, nothing stored, exports to SVG, PNG, and a Mermaid erDiagram block for your README. Pro is $9/mo for 500-table schemas. Choose it when the SQL already exists and you want the diagram, not a modelling session.
dbdiagram.io
The established text-to-diagram tool, built on DBML. Best when you are designing a schema from scratch and want a concise notation that generates SQL back out; the October 2026 update made private mode free and unified dbdocs into one $96/yr plan. Choose it when DBML is (or should be) how your team writes schemas — or see the paste-your-SQL comparison.
drawDB
A free, open-source (AGPL-3.0) editor that runs entirely client-side — no account, no table caps, self-hostable via Docker. Draw tables by hand, import SQL scripts, export SQL across dialects. Choose it when you want a capable editor nobody can take away or charge you for.
DrawSQL
A shared visual workspace for a team's schema. The free tier is 15 tables per diagram, public; private diagrams and larger canvases start at $19/mo. Choose it for collaborative schema documentation where public-by-default is a feature — or see the privacy and limits comparison.
QuickDBD
Type in its own shorthand (ref: lines and friends) and the diagram draws as you type — the fastest way to sketch a design that does not exist yet. The free tier is one public diagram, 10 tables; Pro is ~$14/mo. Choose it for speed-sketching, not for documenting a real database.
The one that takes raw SQL
No sign-up, nothing installed — this is the real converter, with a small PostgreSQL sample loaded. Paste your own DDL over it.
Your diagram renders here.
Questions, answered
What is the best free ER diagram tool?
It depends on what you start from. If you already have SQL — a migration, a backup, a dump — ERD Tools turns it into a diagram directly, free up to 50 tables. If you are designing a new schema in text, dbdiagram.io's DBML or QuickDBD's shorthand are the natural fits. If you want an open-source editor you can self-host, drawDB. If you want a team workspace around the schema, DrawSQL.
Are these tools actually free?
Each has a real free tier — the limits are in the table above, with each vendor's pricing page linked. ERD Tools is free with no diagram count: unlimited diagrams up to 50 tables each, no account.
Which free tools take SQL directly?
ERD Tools pastes your SQL as written, including full pg_dump and mysqldump files. drawDB imports SQL scripts into its editor. dbdiagram.io imports SQL too, but converts it into DBML, its own notation, as part of the import.
Do any of these store my schema?
ERD Tools stores nothing — the paste is parsed, the diagram renders in your browser, and there is no schema database. The account-based tools store the diagrams you save with them, which is how saving works; check each vendor's privacy page for details.
Deeper comparisons
- dbdiagram.io alternative — no DBML to learn
- DrawSQL alternative — 50 tables free, nothing public
- SQL to Mermaid — text blocks for READMEs and PRs
- SQL to ER Diagram — all seven dialects