NocoDB

NocoDB turns any database into an Airtable-like interface with relations, forms, API access, and automations. Connect it to your existing Postgres, MySQL, or SQLite database and you get a spreadsheet UI on top of your real data. No migration, no data lock-in.

The core product is strong: grid views, gallery views, kanban boards, form builder, REST API auto-generated for every table, and role-based access control. It replaces Airtable for most use cases, and your data stays in your own database.

Self-hosted is free under an AGPL-like license. NocoDB Cloud exists with a free tier (unlimited bases, 1,000 rows per base) and paid plans starting at $12/user/mo for the Team tier with more rows and advanced features. Baserow is the main open source alternative, MIT licensed, similar features, actively developed. If you're already paying for Airtable and it works, the switching cost may not be worth it unless self-hosting matters to you.

The catch: the license changed from MIT to a more restrictive one. Check the current terms if you're embedding it in a commercial product. Performance can get sluggish with very large datasets (100k+ rows in a single view). The automations are basic compared to what you'd build with n8n or Zapier. And development velocity has flatlined recently.