SQL Playground

Yes. It's SQLite compiled to WebAssembly, running fully in your browser. Every query executes against a genuine SQLite engine, so JOINs, GROUP BY, subqueries, CTEs, window functions, and CREATE/INSERT/UPDATE/DELETE all behave exactly as they would on a server. Nothing is uploaded; the database lives in memory on your device and is gone when you close the tab (unless you export it).

Yes. Click 'Open .sqlite' and choose a SQLite file (.sqlite, .db, or .sqlite3) to load it locally. The schema panel updates and you can query it immediately. Because everything runs in your browser, your file is never sent anywhere. Use 'Reset' to return to the built-in sample database.

Everything SQLite supports, which is a large, standards-based subset of SQL: joins, aggregates and GROUP BY, subqueries, common table expressions (WITH), window functions, CASE expressions, and full DDL/DML (CREATE, ALTER, INSERT, UPDATE, DELETE). Note it's SQLite's dialect, so vendor-specific features from MySQL, PostgreSQL, or SQL Server may differ.