HeroTools / Text & Code
Local · Private · Free

SQL Playground

Write and run real SQL against a full SQLite database — entirely in your browser. A sample dataset is ready to query, or import your own CSV as a table. Nothing is uploaded.

⚙️ Heads up: the first time you run a query, your browser downloads a one-time SQLite engine (~1 MB). After that it runs fully on your device, even offline — your data and queries are never sent to a server.

Downloading SQLite engine…
Ctrl/⌘ + Enter to run
Examples

A real database that never leaves your laptop

This is a full SQLite engine (sql.js, compiled to WebAssembly) running inside the page — the same SQL you'd write against a production database. Prototype a query, learn JOINs and aggregates, or load a CSV export and slice it with SQL. Everything stays in memory on your device: no account, no upload, no row limits, and it keeps working offline once the engine is cached.

About SQL Playground

SQL Playground is a free, private text & code tool that runs entirely in your web browser. Run SQL on an in-browser SQLite database; import CSVs as tables (one-time engine download). Because everything happens locally on your device, your files and data are never uploaded to a server, there is no sign-up or installation required, and it keeps working offline. It is handy for sql, sqlite, query, database. Like every HeroTool by Digital Heroes, SQL Playground is 100% free with no limits.

How to use SQL Playground

  1. Open SQL Playground — it runs entirely in your browser, with no signup.
  2. Paste or type your text or code into the editor.
  3. Adjust the options to match exactly what you need.
  4. Copy or download your result — it is free, and your data stays on your device.

Frequently asked questions

Is SQL Playground free?

Yes — SQL Playground is completely free for everyone. No sign-up, no account and no usage limits.

Is it private? Are my files uploaded anywhere?

No. SQL Playground runs entirely in your browser on your own device, so your data never leaves your computer and nothing is uploaded to a server.

Does it work offline?

Yes. HeroTools is a Progressive Web App — once the page has loaded it keeps working offline, and you can install it as an app from your browser.

Do I need to install anything or create an account?

No. Just open the page and start using it. Installing it as an app is optional and only adds offline convenience.

What does SQL Playground do?

Run SQL on an in-browser SQLite database; import CSVs as tables (one-time engine download).

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