Free online data tools

Loads a .parquet file with DuckDB-Wasm so you can browse rows, see column types, query it in SQL and save a CSV or JSON copy.

Turns a JSON sample into SQL CREATE TABLE statements.

Treats an uploaded CSV as a database table so you can filter and aggregate it with SELECT statements.

Opens an Avro file and displays its records and schema.

Compares two CSV files and highlights changed rows and cells.

Edits CSV in a spreadsheet-style grid in the browser.

Generates random CSV rows with chosen column types for testing.

Splits a large CSV into smaller files by row count.

Checks CSV for consistent columns, quoting and encoding problems.

Combines several CSV files into one.

Converts a Parquet file to CSV.

Opens a Parquet file and shows its rows and schema in the browser.

Generates random JSON documents from a template.

Generates random XML test documents.

Runs SQL against an SQLite database in the browser.

Builds random test datasets from a field list and exports them in several formats.