Parquet to CSV Converter
Handle Million Rows in Your Browser

Convert Apache Parquet files to CSV format instantly in your browser. DuckDB-WASM reads Parquet natively — Snappy, Gzip, and Zstd compression are automatically handled. No file upload, no server processing.

Drag & drop your file here, or browse

Accepts: .parquet (up to 50 MB)

Your data stays in your browser. By using this tool, you agree to our Terms and Privacy Policy.

How to Convert Parquet to CSV

Drag & drop your .parquet file or click "browse" to select it.

DuckDB-WASM reads the Parquet file natively, auto-detecting schema and decompressing data.

Preview the CSV output with column headers, data types, and row data.

Click the download button to save the CSV file.

Features

100% Browser-Based: Your data never leaves your device. Processed locally via WebAssembly — no server upload, no privacy concerns.
Native Parquet Reading: DuckDB-WASM reads Parquet files natively with full schema detection. Snappy, Gzip, and Zstd compression are automatically handled.
Type-Aware Conversion: Dates, timestamps, and numeric types from the Parquet schema are correctly formatted in the CSV output.

Parquet vs CSV: What's the Difference?

Apache Parquet is a columnar binary format optimized for analytics, with built-in compression and strict type preservation. CSV (Comma-Separated Values) is a simple text-based tabular format that works with virtually any tool.

	Parquet	CSV
Storage	Columnar binary	Row-based text
File size	3-10x smaller (compressed)	Larger (no compression)
Data types	Integer, Float, Date, Boolean (strict)	Everything is a string
Readability	Requires specialized tools	Opens in any text editor
Common use	Data lakes, Spark, BigQuery, DuckDB	Data exchange, Excel, text processing

Benefits of Converting Parquet to CSV

Universal compatibility — CSV files can be opened by any text editor, Excel, database, or programming language
Human readable — unlike binary Parquet, CSV can be directly inspected as text
Data pipeline integration — most ETL tools, databases, and legacy systems import CSV natively

Frequently Asked Questions

Is my data uploaded to a server?

No. Your file never leaves your browser. All processing happens locally using DuckDB-WASM. No data is sent to any server.

What Parquet compression formats are supported?

DuckDB-WASM natively supports Snappy, Gzip, Zstd, and uncompressed Parquet files. Decompression is handled automatically — no extra configuration needed.

Why is the file size limit 50MB?

Parquet uses columnar storage with strong compression. A 50MB Parquet file can expand to 150–500MB of CSV text. We limit input size to prevent browser memory issues. Even at 50MB, you can convert millions of rows.

Are column types preserved?

Yes. DuckDB reads the full Parquet schema including data types. Dates are formatted as ISO 8601, timestamps include time components, and numeric types maintain precision in the CSV output.