How to Compare Database Schemas Before Deploying
A step-by-step workflow for catching schema drift between staging and production.
Paste two CREATE TABLE dumps into your browser. Spot every table, column, index, and constraint change instantly. Get ready-to-run ALTER TABLE scripts for PostgreSQL, MySQL, SQL Server, SQLite, or Oracle â all without installing anything.
No account required. No data leaves your device.
The most comprehensive free browser-based schema diff tool.
Not a line-by-line text diff. SchemaLens understands CREATE TABLE, ALTER TABLE, indexes, constraints, triggers, views, and functions.
PostgreSQL, MySQL, SQLite, SQL Server, and Oracle. Dialect-aware migration generation means you get valid ALTER TABLE syntax every time.
Catches dropped columns, NOT NULL without defaults, type narrowing, and missing indexes before they hit production. Includes a 0-100 risk score.
Download your diff as Markdown, PDF, raw SQL, JSON, Prisma schema, or Drizzle TypeScript. Share diffs via URL with teammates.
Your schema never leaves the browser. Compare production schemas safely without uploading sensitive table structures to a third-party server.
SQL validator, formatter, schema doc generator, ER diagram generator, index analyzer, health check, CSV/JSON to SQL converters, and more.
Run pg_dump --schema-only, mysqldump --no-data, or .schema on both databases.
Copy the SQL into the two editor panes. Select your SQL dialect from the dropdown.
See added tables, dropped columns, type changes, and constraint modifications highlighted in color.
Export ALTER TABLE scripts, save as Markdown, PDF, or raw SQL. Run in staging, then production.
Choose your dialect for tailored migration generation.
SERIAL, IDENTITY, ENUM types, arrays, JSONB, quoted identifiers, triggers, and functions.
AUTO_INCREMENT, CHARACTER SET, COLLATE, backtick identifiers, generated columns, and inline FKs.
INTEGER PRIMARY KEY, AUTOINCREMENT, limited ALTER TABLE support with honest workarounds.
IDENTITY, bracket identifiers, named default constraints, CLUSTERED/NONCLUSTERED indexes.
GENERATED ALWAYS AS IDENTITY, VARCHAR2/NUMBER types, tablespace clauses, and partitioned tables.
A step-by-step workflow for catching schema drift between staging and production.
Stop writing migration scripts by hand. Learn how automatic generation works for PostgreSQL, MySQL, and SQL Server.
Learn how to catch dropped columns, missing indexes, and type changes before they cause incidents.
SchemaLens generates your ALTER TABLE scripts in seconds. Free for up to 10 tables. Pro starts at $12/mo with a 14-day money-back guarantee.
No credit card required. No data leaves your browser.