SchemaLens is a free database migration review tool. Paste your old and new schema, spot breaking changes, score the risk, and export the exact ALTER TABLE script — all in your browser.
Free forever — unlimited tables, full migration SQL, rollback scripts, and ORM export.
See exactly what changed between two CREATE TABLE dumps. Added tables, dropped columns, type changes, and constraint diffs are color-coded.
SchemaLens flags column drops, table drops, NOT NULL additions without defaults, type narrowing, and other changes that can break production.
Every diff gets a numeric risk score so reviewers know whether a migration is safe, cautionary, or dangerous at a glance.
Generate forward and rollback scripts for PostgreSQL, MySQL, SQLite, SQL Server, and Oracle. Copy, review, deploy.
Generate a shareable link to the diff and post it in your PR, Slack, or ticket. Everyone reviews the same analysis.
All parsing runs in your browser. Your schema dumps never touch SchemaLens servers.
Manual review is great. Automatic review on every PR is better. Add SchemaLens to your pipeline so no migration reaches production unreviewed.
Posts a schema diff comment on every PR with risk score and migration SQL.
Set Up →Generate a workflow for GitHub Actions, GitLab, Jenkins, CircleCI, or Bitbucket.
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