100% In-Browser · DuckDB Wasm · Zero Uploads

Universal In-Browser Data Converter

Transform datasets between Apache Parquet, Excel (.xlsx), CSV, and JSON with ZSTD compression and instant downloads in client-side WebAssembly.

Key Features & Client-Side Capabilities

  • All-in-One Format Conversion: Effortlessly switch between CSV, Excel, Parquet, and JSON in one unified workspace.
  • 100% Client-Side Privacy: All conversions run strictly in local browser memory. Sensitive datasets are never sent to external servers.
  • High-Ratio ZSTD Compression: Compress bulky text spreadsheets into high-speed columnar Parquet files up to 90% smaller.

Frequently Asked Questions

Which formats can I convert between?

You can convert between CSV, TSV, Microsoft Excel (.xlsx), Apache Parquet, and JSON / NDJSON in any combination.

Do my files get uploaded to a cloud server?

No. Conversions run entirely inside your browser tab using DuckDB-Wasm and SheetJS in local RAM.