CSV to Parquet Converter
Convert CSV files into compressed .parquet files for analytics, warehouses, notebooks, and local data sharing. After conversion, validate the output with the Parquet Viewer or Parquet Metadata Reader.
Quick start
- 1
Upload your CSV file
Drag-and-drop a CSV file or click to browse. Everything stays in your browser.
- 2
Select a delimiter
Choose the delimiter used in your CSV — comma, tab, semicolon, or pipe.
- 3
Convert to Parquet
Click convert and your CSV is transformed to Parquet format using WebAssembly.
- 4
Download the Parquet file
Download the resulting Parquet file directly from your browser.
Data stays on your device
All processing runs locally in your browser. Nothing is sent to any server.
Our CSV to Parquet converter uses WebAssembly to convert your CSV files directly in the browser. Choose the delimiter, create a compressed Parquet file, and keep your data on your device. Parquet is a columnar storage file format optimized for analytics, efficient storage, and modern data processing tools.
0 bytes
Data transmitted
4
Delimiters supported
Automatic
Compression
100% Free
Our online CSV to Parquet converter is completely free to use, with no hidden costs or subscriptions.
Privacy-Focused
Your data never leaves your device. All processing happens locally in your browser using WebAssembly.
Fast and Efficient
Quickly convert even large CSV files to optimized Parquet format with our WebAssembly engine.
No Installation Required
Use our converter directly in your web browser, no software installation needed.
Is this CSV to Parquet converter private?
Yes. The converter runs entirely in your browser using WebAssembly. Your data never leaves your device.
What delimiters are supported?
We support comma, tab, semicolon, and pipe delimiters. Select the appropriate one before converting.
What is the advantage of Parquet over CSV?
Parquet is a columnar storage format optimized for analytics. It offers better compression, faster query performance, and supports complex nested data structures.
Can I use this tool offline?
Yes. Once the page finishes loading, you can disconnect from the internet and continue converting files offline.
Can I inspect the Parquet output after conversion?
Yes. Open the downloaded file in the Parquet Viewer to preview rows, or use the Schema Reader and Metadata Reader to validate field types, row groups, compression, and statistics.
Can I convert the Parquet file back to CSV?
Yes. Use the Parquet to CSV converter when you need a spreadsheet-friendly copy of the Parquet output.
Advantages of Parquet Format
Parquet is a columnar storage file format optimized for analytics. It's highly efficient in both storage and performance while supporting modern data processing tools. After conversion, use the Parquet Schema Reader to verify field types or the Parquet Metadata Reader to inspect row groups and compression.
How it works
Our tool uses WebAssembly to convert your CSV to Parquet directly in the browser. This ensures that your data never leaves your device. If you later need spreadsheet output again, convert the result back with the Parquet to CSV Converter.
Parquet Structure
Understanding the structure of Parquet files can help appreciate its efficiency. A Parquet file is organized into rows and columns, but the data is stored in columns, allowing for the following structure:
- Column Chunks: Each column is divided into chunks, which are then stored in separate pages. This structure facilitates efficient data compression and encoding.
- Page Types: There are three types of pages - data pages, dictionary pages, and index pages, each serving a specific purpose in data storage and retrieval.
- Row Groups: A set of column chunks that roughly correspond to a block of rows, allowing for more efficient reads of specific rows.
- Metadata: Contains information about the file's schema, version, and other attributes necessary for processing the file.
Related tools
Parquet Reader and Viewer
Open the Parquet output to preview rows, schema, and metadata.
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Parquet Schema Reader
Check generated field names, data types, and nested structures.
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Parquet Metadata Reader
Inspect row groups, column chunks, compression, and statistics.
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Parquet to CSV Converter
Convert Parquet files back to CSV for spreadsheets.
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