A real SQL playground with guided exercises. Write and run queries instantly on a SQLite engine built into your browser — nothing to install, nothing to sign up for.
What you can practice here
This free online SQL practice page ships 49 curated exercises across 3sample databases (Employees & Departments and ShopCo Orders and Fintech Transactions). Every exercise has a hint and a reference solution, and your query results are checked against it instantly. Prefer to explore? Switch to the free playground mode and run any SQL you like.
Yes. The playground and all 49 exercises are completely free with no signup, no usage limits, and no credit card. A free account is only needed if you want to practice the full interview question bank with saved progress.
Do I need to install anything to practice SQL?+
No. Queries run on a real SQLite engine compiled to WebAssembly, entirely inside your browser. It works on any modern laptop, tablet, or phone.
Is my data private?+
Yes. Everything executes locally on your device — your queries and results never leave the browser and nothing is uploaded to a server.
Which SQL dialect does the playground use?+
SQLite (via WebAssembly). Core SELECT, JOIN, GROUP BY, window-function, and subquery syntax you practice here transfers directly to PostgreSQL, MySQL, and SQL Server.
What SQL topics do the exercises cover?+
49 curated exercises across 3 sample databases (HR, e-commerce, and fintech) progress from SELECT, WHERE, and ORDER BY through JOINs, GROUP BY, HAVING, LIKE, CASE, date and string functions, and NULL handling, up to CTEs, UNION, window functions, and correlated subqueries — each with hints and a reference solution.