Step 1 / source
Choose the source
Drop one file here
Choose the one xlsx worksheet you want to turn into utf-8 ndjson records.
Checking publication status...LOCAL TABLE CONVERTER / EXCEL TO NDJSON
Excel to NDJSON
Export one XLSX worksheet as one flat JSON object per line using stored cell results and explicit empty-cell handling.
Processed in this browserOne unencrypted .xlsx file up to 15 MB and 50 worksheets. The selected tab supports one header row plus 50,000 records, 200 columns, 1,000,000 cells, and 20 MB output.
XLSX - one NDJSON stream
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 unencrypted .xlsx file up to 15 MB and 50 worksheets. The selected tab supports one header row plus 50,000 records, 200 columns, 1,000,000 cells, and 20 MB output.
Plain-language method
How Excel to NDJSON works
The converter reads one explicit worksheet without recalculating formulas, treats the first non-empty row as normalized property names, skips fully blank data rows, converts stored cell displays to text, applies the selected empty-cell rule, and writes one independently parseable JSON object per line.
- 01Choose a valid source
Use one rectangular worksheet with a header row. Save current formula results in the workbook before conversion and avoid merged or presentation-only layouts.
- 02Review the conversion choices
Omit removes blank properties; Null keeps a stable record shape. LF or CRLF changes line separators only.
- 03Inspect the separate result
The result ends in _nirmion_tools.ndjson. Each physical line can be parsed independently and retains worksheet cell displays as JSON strings.
Useful when
Practical jobs this tool handles
- Prepare line-oriented import fixtures from Excel.
- Feed a bounded worksheet export into a streaming pipeline.
- Review one record per line in version control.
Before converting
Check the source and destination rules
- Confirm the selected worksheet number.
- Review normalized and duplicate headers.
- Choose the expected blank-cell contract.
Know the boundary
Know what the destination format cannot keep
Worksheet values are exported as displayed text, so Excel numeric, date, boolean, and formula-result types are not guaranteed to survive as JSON types. Styling and additional worksheets are not included.
Quick answers
Questions before you convert
The conversion contract is deliberately explicit.
Are formulas recalculated?
No. Only saved workbook results are read.
Why are numbers quoted?
Text preservation avoids changing identifiers and regional displays.
Can all worksheets be combined?
No. One explicit tab keeps record origin and schema reviewable.