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Data format

NDJSON converter

A .ndjson file is Newline Delimited JSON — the same one-JSON-value-per-line layout as JSON Lines, under the name used by the specification published at ndjson.org. In practice the two extensions are interchangeable, and a converter that reads one reads the other.

Private for supported formats — processed in your browser

Convert supported files

Runs on your device

Drop NDJSON files here

Batch files can each use a different output. Nothing uploads for local conversions.

Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.

Where NDJSON comes from

NDJSON was written up as an explicit specification in 2013–2014, in parallel with the JSON Lines convention, by people who wanted the streaming layout to have a name and a MIME type (application/x-ndjson) rather than remaining folklore. The duplication has never been resolved: two names, one format, chosen mostly by which ecosystem a tool came from.

How NDJSON works

  • Each line holds one complete JSON value, terminated by \n; the specification explicitly forbids embedded newlines inside a record.
  • The registered media type is application/x-ndjson, which is the one thing that distinguishes it from JSON Lines.
  • Records are self-contained, so a stream can be consumed and discarded incrementally.
  • No enclosing array means the file is not itself a valid JSON document.
  • Parsers are expected to skip blank lines rather than error on them.

When to use NDJSON

  • HTTP streaming APIs that emit results as they are produced
  • Log shipping and event ingestion pipelines
  • Datasets appended to continuously by multiple writers
  • Converting a stream into a spreadsheet for inspection

Strengths and limitations

Strengths

  • Has an actual specification and registered media type, unlike the JSON Lines convention
  • Streams cleanly over HTTP without buffering the whole response
  • Line boundaries make parallel processing trivial

Limitations

  • Two names for one format causes real tooling confusion
  • No schema enforcement across records
  • Cannot be validated as a single JSON document

Compatibility

Supported by the same data ecosystem as JSON Lines, and used by several HTTP streaming APIs that set the application/x-ndjson content type. Novus Convert reads it locally and converts to JSON, CSV, XLSX and ODS.

None beyond the fields each record carries.

Convert NDJSON to another format

Convert other formats to NDJSON