SchemaForge is a free schema designer that runs in your browser. Draw tables and relationships, catch mistakes as you go, then generate SQL for four databases, migration scripts and EF Core classes.
No install. Your schemas stay in your browser.
One tool for designing, checking, changing and using a schema.
Design once in SQL Server terms, then pick the database you actually run. Types, defaults, identity columns and constraints are translated, and anything that can’t be expressed exactly is listed rather than silently changed.
Save a version, keep designing, and SchemaForge writes the script that turns the old database into the new one — and the script that undoes it.
The playground builds a PostgreSQL database from your design, fills it with believable fake data that respects every key and type, and gives you a query box.
Get entity classes and a DbContext configured with the Fluent API so the model matches your design: names, types, keys, indexes, relationships and delete behaviour.
Describe a database or a change in plain words. You get a proposal with every change listed, checked by the same validator as your own edits. Nothing touches your schema until you press Apply, and it’s one undo step.
Small things that matter when the schema is real.
Missing keys, mismatched types, bad names, impossible cascades — with a one-click fix for most of them.
The whole schema lives inside the link, so nothing is uploaded. Anyone can look, export, or save their own copy.
PNG and SVG pictures, Mermaid for your docs, DBML for dbdiagram, and JSON to back up or move a schema.
Every edit is undoable. Work is saved as you go, in your own browser.
Tested with 100 tables and thousands of columns, with one-click auto-layout to tidy them.
Works on a laptop, a tablet or a phone.
A schema tool is only useful if the output actually works. So it is tested against the real things.
Generated SQL is run on real SQL Server, PostgreSQL, MySQL and SQLite, and what they build is compared with your design.
Random edits are applied to real databases with the migration script, then undone with the rollback — and the result must match.
The generated C# is compiled with the .NET compiler, and EF Core builds the database from it to confirm it matches.
Sign in with Google or an email and password.
| No account needed | With a free account |
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Short answers.
Your schemas are saved in your own browser, not on a server. Export a JSON file now and then as a backup — clearing the browser’s site data deletes them. If you create an account, only your email and name are kept (by the sign-in service). A share link carries the schema inside the link itself.
No. SchemaForge is design-first: you can import a T-SQL script of an existing database, and you take the generated SQL, migration or code to wherever you run it. It never holds your database credentials or your data.
Only for the assistant. You paste your own free Gemini key (from Google AI Studio) into its settings; it stays in your browser and goes only to Google. The assistant sends the structure of your schema — table, column and index names, types and comments, never data rows.
You design in SQL Server terms and generate SQL Server, PostgreSQL, MySQL or SQLite. Where a database can’t express something exactly, the notes tell you what was changed.
It can be wrong, which is why it only ever proposes. You see every change, SchemaForge checks the result with its own validator (and asks the model to fix its answer once if something is off), and you decide whether to apply it.
Yes — the layout adapts, and you can view, edit and export. A larger screen is simply nicer for big diagrams.
Start from a template or import a script — it takes under a minute to see your schema on the canvas.
Open the appYour schemas are stored in your browser and are not sent to us. Accounts use Supabase: if you sign in we keep your email address (and your name and picture if you use Google) only to sign you in. The AI assistant, when you use it, sends the structure of your schema to Google’s Gemini service with your own key; use a key you can revoke. Share links contain the schema, so anyone who has the link can read it. We don’t run ads or sell data.
