Step 1 / source
Choose the source
Drop one file here
Choose the header-based csv table you want to turn into ndjson object stream.
Checking publication status...LOCAL DATA CONVERTER / CSV TO NDJSON
CSV to NDJSON
Convert each row of a rectangular CSV table into one compact JSON object per line for streaming and batch workflows.
Processed in this browserOne UTF-8 .csv file up to 5 MB, 50,000 records, 200 columns, 1,000,000 cells, and 20 MB output.
CSV - 50,000 records
No file upload
This operation runs with browser APIs. Nirmion receives catalogue requests, not the selected source bytes.
Original stays unchanged
The converter creates a separately named output. It never writes back into the source file.
Bounded work
One UTF-8 .csv file up to 5 MB, 50,000 records, 200 columns, 1,000,000 cells, and 20 MB output.
Plain-language method
How CSV to NDJSON works
Nirmion parses one rectangular table, creates stable property names from the header row, maps each non-empty row to a JSON object of string or null values, serializes each object compactly, and writes exactly one object per physical output line.
- 01Choose a valid source
Use a header row and balanced quoting. A malformed row stops the conversion rather than disappearing silently.
- 02Review the conversion choices
Choose the actual delimiter and the receiving system's line ending. Null retains empty properties; Omit removes them.
- 03Inspect the separate result
The .ndjson download has no surrounding array brackets or commas. Every line can be parsed independently.
Useful when
Practical jobs this tool handles
- Prepare CSV records for a streaming import.
- Create line-oriented test fixtures.
- Move reviewed tabular exports into log-style processing.
Before converting
Check the source and destination rules
- Verify the delimiter and headers.
- Choose the empty-property contract.
- Confirm the output line count matches data rows.
Know the boundary
Know what the destination format cannot keep
NDJSON is not one standard JSON value. Values remain strings or null, and software that expects a JSON array will not accept the complete file directly.
Quick answers
Questions before you convert
The conversion contract is deliberately explicit.
Does each line contain valid JSON?
Yes. Every non-empty output line is one complete compact object.
Are commas written between lines?
No. Newlines define records in NDJSON.
Are source numbers typed automatically?
No. CSV text remains string data.