CSV to PARQUET

convert csv files to parquet in your browser with auto delimiter detection, batch processing, and zip export.

how to use

  • 1. drop or choose csv files (up to 10 MB each).
  • 2. confirm the detected delimiter or pick another one.
  • 3. download parquet files individually or export all as a zip.

Do you need Example files or want to convert parquet to csv?

CSV Example files

We provide you with some sample files containing 1k, 10k, and 100k data entries, so you can easily test whether our program meets your requirements.

File link download
1 user-email-1k.csv https://file.parquettocsv.online/examples/user-email-1k.csv
2 user-email-10k.csv https://file.parquettocsv.online/examples/user-email-10k.csv
3 user-email-100k.csv https://file.parquettocsv.online/examples/user-email-100k.csv

CSV to Parquet Converter - Client Only, Multiple and Free

Convert CSV files to optimized Parquet files in seconds. This CSV to Parquet converter runs locally in your browser, supports multiple files, and keeps your data on your device.

What is CSV

CSV (Comma-Separated Values) is a plain-text table format. It is widely used for data exchange, spreadsheets, and quick data exports.

What is Parquet

Parquet is a columnar storage format optimized for analytics. It offers better compression and faster column-based queries compared with row-based formats.

Why use this CSV to Parquet tool

  • Client-side conversion with DuckDB WASM for fast, accurate results.
  • Auto delimiter detection with manual override when your CSV uses a custom separator.
  • Batch processing with per-file progress and a clear queue view.
  • One-click ZIP export for multiple Parquet files.

How to use

  1. Upload one or more CSV files.
  2. Review the detected delimiter and change it if needed.
  3. Download individual Parquet files or export everything as a ZIP.

related tools:

  • Merge CSV: merge multiple CSV files into one.

Delimiter examples

  • Comma: , (standard CSV)
  • Semicolon: ; (common in EU locales)
  • Tab: \t (TSV)
  • Pipe: | (log-style exports)

Use cases

  • Store large CSV datasets more efficiently in Parquet.
  • Speed up analytics workloads that prefer columnar storage.
  • Prepare files for data lakes, BI tools, and data engineering pipelines.

FAQ

Is my data secure?

Yes. All data is processed locally in your browser and never sent to a server.

Does it work with different delimiters?

Yes. The tool auto-detects delimiters and lets you manually choose another option.

Is this an online CSV to Parquet converter?

Yes. It runs in the browser and processes files locally on your device.

Is there a file size limit?

Currently, each file is limited to 10 MB.

Do I need to create an account?

No. This tool is completely free.