---
title: SQL Query Playground
emoji: 🦆
colorFrom: indigo
colorTo: gray
sdk: static
pinned: true
license: mit
short_description: Real SQL against DuckDB WASM — runs in your browser
---

# SQL Query Playground

Write and run **real SQL against a seeded warehouse** — DuckDB compiled to
WebAssembly, executed entirely in your browser. Nothing is uploaded, no server
exists: the database, the engine and the results all live on your machine.

- **55 tested templates** — window functions, cohort queries, funnel metrics,
  date arithmetic — every template is also executed in CI against the same data.
- Schema browser for the four-table warehouse (1,000 customers, 5,000 orders,
  12,663 line items), seeded deterministically.
- Ctrl+Enter to run; query timing and row counts shown on every execution.

Not a simulation: every query is parsed, typed and executed by a real DuckDB
engine. Errors surface as data — the way production pipelines treat failures.

- Code + template library: [sql-query-builder on GitHub](https://github.com/Reaver1000/sql-query-builder)
- Built by [David Buchan](https://reaver1000.github.io) — AI, automation and data work