SmartQueryTools

Convert NDJSON to Parquet Online

Convert NDJSON files to Parquet format directly in your browser. No upload required — your data never leaves your device.

Drop your .ndjson file here

or click to browse — max 50 MB

About this conversion

This tool converts NDJSON files to Parquet format directly in your browser — no account required, no file upload, no waiting for a server. It processes your data entirely within your browser using WebAssembly, so nothing ever leaves your device.

The tool preserves all columns and data types from your source file and writes a valid Parquet file ready to download. Large files are handled efficiently using a vectorised columnar engine.

Frequently Asked Questions

What is Parquet format?

Parquet is an open-source columnar storage format designed for efficient analytics. It compresses far better than CSV and is natively supported by Spark, Athena, BigQuery, Pandas, and DuckDB.

Is my NDJSON data private?

Yes — completely. Your file is never uploaded to any server. All conversion happens inside your browser using WebAssembly — locally, with no upload. Once you close the tab, nothing is retained.

What is the maximum file size?

The free limit is 50 MB. For larger files, performance depends on your device's available memory — most modern machines can handle 500 MB to 1 GB comfortably.

What is the difference between NDJSON and Parquet?

Both NDJSON and Parquet are common data formats used in engineering and analytics workflows.

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