Converter
Parquet is great for storage and analytics, but sooner or later someone needs the data in CSV — for Excel, a legacy tool, or a colleague who just wants a spreadsheet-friendly file.
viewparquet converts Parquet to CSV entirely in your browser. The file is parsed locally with DuckDB-WASM and the CSV is generated on your machine, so nothing is uploaded — safe even for confidential data. Unlike a dumb converter, you can run SQL first: pick columns, filter rows, or join files, and export exactly the slice you need.
Drag your .parquet file into viewparquet, or open it from S3 or a URL.
Skip this for a full-file export. Or write a query — SELECT the columns you need, add a WHERE clause, or LIMIT the rows — and export the result instead of the whole file.
Click Export and choose CSV. The file is written locally by DuckDB and downloads straight from your browser.
Use a browser-based converter. Open the .parquet file in viewparquet and click Export → CSV — no Python, pandas, or install needed, and the conversion runs locally so the data is never uploaded.
No. viewparquet runs DuckDB compiled to WebAssembly inside your browser tab. Both reading the Parquet file and writing the CSV happen on your device — you can confirm in the DevTools Network panel that no data leaves.
Yes. Run a SQL query first — for example SELECT id, name, amount FROM data WHERE amount > 0 — and export the query result. This produces a smaller, cleaner CSV than converting the whole file.
CSV is plain text with no type information, so types are represented as text: timestamps and decimals are written out as strings and must be re-parsed by whatever reads the CSV. If a downstream tool supports Parquet or JSON directly, prefer those to keep types intact.
With the DuckDB CLI it is one statement: COPY (SELECT * FROM read_parquet('data.parquet')) TO 'data.csv' (FORMAT CSV, HEADER). A browser viewer is faster for one-off conversions; the CLI is better for scripts.
Size is limited mainly by your browser’s available memory, not a fixed cap. viewparquet streams and paginates, and exporting a filtered SQL result instead of the full file keeps memory use low for very large datasets.
Drop a Parquet, GeoParquet, CSV, or JSON file into viewparquet — browse rows, run DuckDB SQL, and export results, all locally in your browser. Nothing is uploaded.