erd.tools
Free · No sign-up · Nothing installed

SQL to ER Diagram

Paste your DDL — get a diagram worth putting in your docs. Raw pg_dump and mysqldump files welcome; noise stripped, foreign keys reattached.

SQL input — CREATE TABLE · DDL · dumpauto-detect
Sample: · ·
Diagram—

Your diagram renders here.

How it works

Three steps, no account

  1. 01Paste your SQL

    CREATE TABLE statements, ALTER TABLE constraints, or an entire schema dump. Auto-detect picks the dialect.

  2. 02Get the full picture

    Every table, column and foreign key drawn column-to-column, ON DELETE behavior labelled on each edge.

  3. 03Export or share

    SVG or PNG for docs and PRs, Mermaid for your README, or a share link your team can open.

What it handles

The parts other converters drop

  • Multiple dialects — PostgreSQL, MySQL, SQLite, SQL Server, BigQuery via auto-detect
  • Raw dump files — INSERT rows and session noise stripped; only the schema survives
  • Separated foreign keys — ALTER TABLE … ADD CONSTRAINT, the way pg_dump actually writes them
  • Column-level FK connectors — lines anchor to the exact column row, CASCADE labelled
  • Editorial mode — one click to the 5-table subsystem worth printing, caption written
  • No sign-up — free up to 50 tables; your SQL is used only to render your diagram
FAQ

Questions, answered

How do I create an ER diagram from SQL?

Paste your CREATE TABLE statements above and hit Generate. The parser reads tables, columns, types and foreign keys, then lays out the diagram automatically — no drawing, no account.

Which SQL dialects are supported?

PostgreSQL, MySQL and SQLite today, with auto-detection. Dialect-specific types (jsonb, AUTO_INCREMENT, IDENTITY) render correctly.

Does it work with pg_dump or mysqldump output?

Yes — paste the raw dump. INSERT rows and session noise are stripped; ALTER TABLE foreign keys are reattached to their tables.

Is it really free?

Generating diagrams is free and unlimited up to 50 tables, no sign-up. Pro ($9/mo) lifts the limit to 500 tables and unlocks watermark-free exports — details on the pricing page.

How is this different from drawsql or dbdiagram?

Those are editors you draw in. This starts from your actual SQL and gets you a finished diagram — with a design that survives being pasted into documentation.

Can I export to Mermaid?

Yes, every diagram exports as a Mermaid erDiagram block for your README or docs site.

Do you connect to my database?

No. Nothing to configure and no credentials — you paste SQL, you get a diagram.