How do I run SQL on a CSV file?

Drop the CSV (or JSON or Parquet) into the tool and write a SQL query against it. You can filter, aggregate, and join just like a database table.

What file formats can I query?

CSV, JSON, and Parquet files are supported.

Is my data uploaded to query it?

No. The query engine runs entirely in your browser, so your data stays local.

All tools/Query & Analyze

SQL on Files

Loading DuckDB… Runs locally

Drop CSV, JSON, Parquet, or SQLite files and run real SQL against them. Powered by DuckDB-WASM — your data never leaves the tab.

Tables

Drop files here or click + Add.

Query

Result

Spinning up DuckDB-WASM…

Run SQL queries directly against CSV, JSON, and Parquet files in your browser — no database to set up. Drop a file, write a SELECT, and explore, filter, join, and aggregate your data instantly. Everything runs locally, so your data stays private.

How to query a file with SQL

1Drop in a CSV, JSON, or Parquet file.
2Write a SQL query against it — SELECT, WHERE, GROUP BY, JOIN.
3View and export the results.

A database for your files, instantly

Sometimes you just need to ask a question of a data file — filter rows, sum a column, join two exports — without importing it into a real database first. Querying the file directly with familiar SQL gives you that power in seconds, and because it all runs in the browser, even confidential datasets never leave your machine.

Frequently asked questions

How do I run SQL on a CSV file?: Drop the CSV (or JSON or Parquet) into the tool and write a SQL query against it. You can filter, aggregate, and join just like a database table.
What file formats can I query?: CSV, JSON, and Parquet files are supported.
Is my data uploaded to query it?: No. The query engine runs entirely in your browser, so your data stays local.