Conversion

NDJSON to JSON

Turn newline-delimited JSON — one record per line — into a single JSON array.

NDJSON (one record per line)

Settings

Output

Result appears here after you select

{ } How to use

  1. Paste the NDJSON, or load a .ndjson / .jsonl file.
  2. Select Process.
  3. The result is one array, ready for any tool that expects normal JSON.

{ } How it works

NDJSON to JSON works on the text you provide. Adjust the options, then select Process ▸ and it runs entirely in your browser — nothing is uploaded to a server — then shows the result in the Output panel.

Inputs

  • NDJSON (one record per line) — paste or type your input in the left panel (use Sample for an example)
  • Indentation — choose one — Minified, 2 spaces, 4 spaces (default: 2 spaces)

Output

JSON — copy it, download it, or switch the Output panel to Tree view to explore it.

{ } Common uses

  • Read a log or export that arrives as one JSON object per line.
  • Get NDJSON into a shape the other tools here can work on.
  • Feed a data pipeline’s output into something that expects an array.

{ } Limitations

  • Blank lines are skipped. A line that is not valid JSON stops the conversion and is named, because silently dropping a record from a log is how a missing entry becomes invisible.
  • The whole file is held in memory as one array, so a very large export is better split first.

{ } FAQ

Is my data uploaded to a server?

No. Everything runs locally in your browser — your files never leave your device.

Can I process more than one file at once?

This tool works on one input at a time.

Is this tool free?

Yes — it’s completely free and needs no sign-up.

What is the difference between NDJSON, JSON Lines and JSONL?

Nothing that matters. All three mean one JSON value per line with no enclosing array, and this handles them all.

Why use NDJSON at all?

Because it can be appended to and read one line at a time. A JSON array has to be closed before it is valid, which makes it a poor fit for a log that is still being written.