NDJSON to JSON Converter
Convert JSON Lines to a JSON array — and back
Runs 100% in your browser — nothing is ever uploaded.
What is NDJSON to JSON?
Paste NDJSON / JSON Lines (one JSON object per line) and get a pretty-printed JSON array — or use the reverse button to turn a JSON array back into NDJSON. Each line is validated separately with clear error line numbers, making it easy to clean log exports, LLM datasets and streaming API dumps.
How to use NDJSON to JSON
- Paste your NDJSON into the input box or click “Load sample” to try it.
- Adjust the options in the toolbar if needed (root name, format, delimiter …).
- Click the convert button — the JSON output appears instantly in the output pane.
- Copy the result with one click or download it as a file.
ConvertLab FAQ
Is the NDJSON to JSON converter free?
Yes — 100% free, no signup, no limits, no watermarks. Use it as often as you like.
Can I convert in both directions?
Yes — the main button converts NDJSON to a JSON array, and the “JSON → NDJSON” button does the reverse, emitting one compact JSON object per line, the format expected by BigQuery, jq streaming and most log pipelines.
Is my data uploaded to a server?
No. Everything runs entirely in your browser with JavaScript — your data never leaves your device, which makes the tool safe even for confidential files.
Are these converters free?
Yes — every ConvertLab tool is 100% free with no signup, no limits and no ad walls.
Is my data uploaded anywhere?
No. All conversions (JSON, CSV, XML, YAML, INI, .env) run entirely in your browser. Nothing ever leaves your device.
Do these tools work offline?
Yes — once the page is loaded, every converter works without an internet connection.