Convert Parquet to CSV in your browser

Parquet is a binary, column-oriented format with compression per column, built for query engines rather than spreadsheets. Excel, Numbers and Google Sheets don't read it, and most online converters either cap the file at a few megabytes or upload it to a server first.

This page runs DuckDB inside your browser tab. It reads Parquet natively, including snappy, zstd, gzip, brotli and lz4 compressed files and files with multiple row groups, and nothing is uploaded unless you press Share.

Excel stops at 1,048,576 rows per sheet and Google Sheets at 10 million cells. The taxi sample on this page has 7.4 million rows and comes out as a 685 MB CSV, which no spreadsheet opens whole. Filter first: passenger_count:>4 tip_amount:>10 keeps 12,546 of them, and Export writes only those.

For a fixed slice, SQL does it: SELECT * FROM data WHERE pickup_at >= '2019-04-15' LIMIT 500000. SQL results are capped at 1,000,000 rows, which is also right under Excel's limit.

UTF-8, comma separated, one header row with the Parquet column names, values quoted where needed. Nulls become empty cells. Timestamps and decimals are written as text in their full precision. Nested columns (lists and structs) are written as JSON text inside the cell, so nothing is silently dropped.

Text cells that start with =, +, - or @ get a leading apostrophe. That stops Excel and Sheets from running a cell like =HYPERLINK(...) as a formula when someone opens the file.

Hide the columns you don't need and they stay out of the CSV. Click a header to sort, shift-click for a second sort key, and the file is written in that order. The column stats panel shows non-null counts, distinct values and min/max, which is a quick way to see which columns are worth keeping.

The same Export menu also writes JSON, JSONL, Markdown (first 1,000 rows) and a fresh zstd Parquet file, if what you really wanted was a smaller Parquet.

A public Parquet file on S3, GitHub or a data portal opens without downloading it first: put the URL after the domain, like rows.page/https://blobs.duckdb.org/data/taxi_2019_04.parquet. Files the source serves with CORS headers load straight into your tab; others go through a proxy that accepts up to 100 MB.

To hand the CSV to someone else, press Share instead of mailing a 200 MB attachment. The link opens the same table, with filters, on their phone.