See it in action
Paste two schemas. Click Compare. Get the diff and migration SQL in seconds.
SchemaLens is a privacy-first schema diff tool for PostgreSQL, MySQL, SQLite, SQL Server, and Oracle. Paste two CREATE TABLE dumps, get a visual semantic diff, and generate ready-to-run ALTER TABLE scripts.
100% client-side. Your schemas never leave your browser.
Paste two schemas. Click Compare. Get the diff and migration SQL in seconds.
100% client-side. Your schema never hits a server. Verify it yourself in DevTools → Network.
Open the URL and diff in 10 seconds. No install, no signup, no backend.
Understands tables, columns, types, defaults, constraints, indexes, triggers, views — not just text.
Risk score (0–100) flags dangerous migrations before they hit production.
Share diffs via base64-encoded URLs. Paste into Slack, email, or PR descriptions.
Run npx schemalens-cli locally or in GitHub Actions, GitLab CI, and Bitbucket Pipelines.
Real, unedited feedback from developers who tried SchemaLens.
"Neat tool. Does it support diffing between branches (e.g., compare staging schema vs production)? That's the main use case I'd want — catching drift before a deploy, not after."
✅ We built it: Git Branch Schema Diff →
"The VS Code extension is nice but I already use SQLTools for schema viewing. What makes this different is the visual diff — but I'd need it integrated into my CI pipeline, not just a manual tool."
✅ We built it: GitHub Action →
"CLI tool is cool but the npm package name is confusing — I expected 'schemalens' to be the CLI but it's actually 'schemalens-engine'. Consider renaming or adding an alias."
✅ We fixed it: npx schemalens-cli — CLI docs →
224 days. 52 blog posts. 72+ micro-tools. One developer. One mission.
Thanks to everyone who upvoted, commented, and shared feedback. You made this possible.
Hey Product Hunt 👋
I built SchemaLens because I was tired of squinting at text diffs between schema dumps and manually writing ALTER TABLE statements. Every deploy felt like a gamble — did I miss a dropped column? Did a foreign key change break something?
SchemaLens is my answer: paste two CREATE TABLE dumps, get a semantic visual diff, and generate ready-to-run migration SQL. Zero backend. Zero signup. Your schemas never leave your browser.
The past 224 days have been a wild ride — 52 blog posts, 72+ micro-tools, 227 SEO landing pages, a CLI, a VS Code extension, and a Chrome extension. All built in public. If you have feedback, a feature request, or just want to say hi, drop a comment below or email me directly.
Thank you for checking it out. — Jochen
No signup required. No data leaves your browser.
