NDJSON Formatter
Format newline-delimited JSON into readable pretty blocks.
What this tool does
Format JSON Lines (NDJSON) input by pretty-printing each line while preserving record boundaries.
Tool interface
Input
Output
Example input
{"id":1,"event":"signup"}
{"id":2,"event":"login"}Example output
{
"id": 1,
"event": "signup"
}
{
"id": 2,
"event": "login"
}Step-by-step instructions
- Paste one JSON object per line.
- Click Transform to validate and format each line.
- Copy or download the formatted NDJSON output.
Common use cases
- Making dense content easier to review and debug.
- Standardizing output before sharing queries or payloads.
- Cleaning generated text for readable documentation.
Improves readability when inspecting log pipelines, event streams, and JSONL exports.
Common mistakes to avoid
- Pasting partial JSON fragments instead of complete valid objects or arrays.
- Assuming nested keys flatten automatically without checking output columns.
- Mixing JSON arrays and objects when the tool expects one specific structure.
Frequently Asked Questions
Will this validate each line?
Yes. Invalid JSON lines return line-numbered errors.
Does it change record order?
No. Output preserves input line order.
What input format does NDJSON Formatter expect?
Use valid JSON input unless the tool explicitly asks for path or pattern syntax first.
What does NDJSON Formatter output?
It returns transformed output you can copy or download as `formatted.ndjson.txt`.
Why might NDJSON Formatter return an error?
Most failures come from malformed input that does not match the expected format.
Does NDJSON Formatter run in the browser?
Yes. Transformations are designed for in-browser usage so you can test and iterate quickly.
Can I copy or download results from NDJSON Formatter?
Yes. You can copy the result or use the download action when file output is available.
Related tools
Related guides
Browse all DataToolbox guides for more workflows.
Related categories
Looking for other utilities in this area? JSON Tools, Developer Data Tools