What is a .parquet file? (Parquet)

Parquet is a columnar storage format built for analytics on large datasets. Instead of storing rows together, it stores each column together, which makes reading a few columns from a huge table fast and highly compressible.

What is a .parquet file used for?

Parquet is the default format for big-data tools like Apache Spark, and for data lakes and warehouses. Because data is grouped by column, a query that touches three columns of a two-hundred-column table reads only what it needs.

Each file begins and ends with the four bytes PAR1, wrapping compressed column chunks and a footer that holds the schema and statistics. It is a binary format, so you read it with a library such as pandas, DuckDB or Spark rather than a text editor.

How to open a .parquet file

The .parquet format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list. For a step-by-step walkthrough, see how to open a .parquet file.

Windows

Python (pandas, pyarrow)
DuckDB
Tad viewer

macOS

Python (pandas, pyarrow)
DuckDB
Tad viewer

Linux

Python (pandas, pyarrow)
DuckDB
Apache Spark

How to convert a .parquet file

You can convert a .parquet file to CSV, JSON, Arrow using a conversion tool or the export menu of an app that opens it.

.parquet file signature (magic bytes)

Programs recognise a .parquet file by the bytes at the start of the file, not by its name. These are the signatures for Parquet. For a full breakdown, see the Parquet file signature page.

Hex signature	Offset	Note
50 41 52 31	0	'PAR1' header
50 41 52 31	-4	'PAR1' footer at end of file

See the full magic-numbers reference for every format.

Frequently asked questions