Universal workbench

NDJSON to Apache Parquet

Create Apache Parquet from NDJSON locally with an explicit tabular schema.

Device-onlyNo uploads. Ever.

Pipelines, branches, presets, naming, and detailed controls

Display

Text sizeDensity High contrast Monospace editor

Quick start

JSON → YAML WebP → PNG SVG → React JSX Plain text → Base64

From

Help me choose the best output Suggested: CSV

What matters most?

Recommendations use the registered target format and tested fidelity classification. They never inspect or upload your content.

01Input

Drop files or a folder hereChoose NDJSON files or a folder — batch input is welcome

Choose files Choose folder

or paste content

02Configure & run

NDJSONApache Parquet

structural conversion · single or batch

Conversion preflightSize, memory, engine, execution, and fidelity before you start

Input: 51 B
Estimated peak memory: 16 MiB
On-demand download: No large engine download
Execution: Responsive local worker
Fidelity: No lossy step declared

What to provideProvide one complete JSON value per non-empty line.What you’ll getProduces a downloadable Apache Parquet file with the correct extension and MIME type.

Output naming & batch behavior

Filename templateBuild the name with the variables below. Duplicate names receive a safe numeric suffix.

Exampleoutput.parquet

Pipeline 1 linear · 0 branches

Why use A → B → C?

A pipeline feeds each result directly into the next compatible converter. Use one when the destination needs an intermediate representation or when you want to inspect and normalize that middle format.

JSON → CSV → XLSX turns records into rows before building a workbook.
Markdown → HTML → DOCX resolves markup before creating a document.
SVG → PNG → PDF intentionally flattens vector artwork before placing it on a page.

Only type-compatible next steps are offered. Lossy steps are marked before you run them.

1NDJSON to Apache Parquetstructural

Add compatible step

Parallel output branchesEach branch receives the final linear result. Branches do not feed or depend on one another.

Add a parallel destination

03Tool output

Produces a downloadable Apache Parquet file with the correct extension and MIME type.Lightweight text routes update after 360 ms. Downloads remain explicit.

Processing happens locally. Your file bytes are never sent anywhere.

About this conversion

How to convert NDJSON to Apache Parquet

Before you start

Provide one complete JSON value per non-empty line.

Accepted: .ndjson, .jsonl · application/x-ndjson

Paste valid NDJSON content, choose files, or drag them onto the drop zone.
Confirm the detected format. Mixed-format batches are flagged before conversion.
Select “Convert on this device.” Produces a downloadable Apache Parquet file with the correct extension and MIME type.

How this converter behaves

SQLite, Parquet, Arrow, Feather, and table documents are decoded into typed rows in browser memory, then re-encoded without a database server.

What happens to your data?

The conversion engine runs in this browser tab. OmniCastConverter has no upload API and never sends your content, file name, or converted result to a server.

Fidelity and limitations

This route is classified as structural. The converter preserves meaning and structure supported by both formats.

Tabular values are preserved, while indexes, constraints, triggers, views, relationships, formulas, custom extensions, and database-specific types are not represented by the canonical dataset.

Try a valid example

The “Use example” action in the workbench loads this exact input. Produces a downloadable Apache Parquet file with the correct extension and MIME type.

{"name":"Ada","score":42}
{"name":"Lin","score":37}