SQL Query Tool
Load one or more files and query them with SQL. Each file becomes a table named after its filename. Everything runs in your browser — your data never leaves your device.
More Power Tools
Data Profiler
Profile any file — row counts, column types, null rates, and statistics.
Join Files
Join two files with INNER, LEFT, RIGHT, or FULL OUTER joins on any key column.
Find Duplicates
Find duplicate rows across any column combination and export the results.
Pivot Table
Build pivot tables from any data file — rows, columns, values, and aggregation.
Data Catalog
Browse free public datasets and query them directly in the SQL editor.
Mock Data Generator
Generate realistic sample data — names, emails, dates, numbers, and more.
Chart Builder
Visualize any data file as a bar chart, line chart, scatter plot, or histogram.
Lookup Tool
Add a column by looking up values from a reference table — like Excel VLOOKUP.
XML to CSV
Convert XML files to CSV, JSON, Parquet, and more — no upload required.
SQL Importer
Import a SQL dump and export the data as CSV, Parquet, or JSON.
Excel Sheet Extractor
Extract any sheet from a multi-sheet Excel workbook and convert to CSV or Parquet.
Frequently Asked Questions
Is my data uploaded to a server?
No. The SQL engine (DuckDB compiled to WebAssembly) runs inside your browser. Files you load are read locally, queries execute on your device, and nothing is transmitted anywhere. Close the tab and everything is gone.
What SQL dialect does the editor use?
DuckDB SQL, which closely follows PostgreSQL syntax. It supports joins, window functions, CTEs, aggregation, string and date functions, PIVOT/UNPIVOT, and more. If you know PostgreSQL, you already know how to use it.
What file formats can I query?
CSV, TSV, Parquet, JSON, NDJSON/JSONL, Excel (XLSX), YAML, and Apache Arrow IPC. Each loaded file becomes a table named after its filename, and you can join tables from different formats in a single query.
Can I query multiple files together?
Yes. Load any number of files and join them like database tables — for example joining a CSV of orders to a Parquet file of customers on a shared key column.
Can I query a file from a URL?
Yes — pass an https URL directly to a read function, e.g. SELECT * FROM read_csv_auto('https://…'). The host must allow cross-origin (CORS) browser requests; the Data Catalog tab lists verified working public datasets.
How large a file can I query?
Files up to 500 MB can be loaded, and performance depends on your device’s memory. Because DuckDB is a vectorised columnar engine, queries over millions of rows typically complete in seconds.