Step 1 / source
Choose the source
Drop one file here
Choose a UTF-8 table where literal tab characters separate fields and rows form one rectangle.
Checking publication status...LOCAL DATA CONVERTER / TSV TO XLSX
Turn a tab-separated UTF-8 table into a genuine XLSX worksheet with optional header styling, frozen navigation, and readable widths.
Step 1 / source
Choose a UTF-8 table where literal tab characters separate fields and rows form one rectangle.
Checking publication status...This operation runs with browser APIs. Nirmion receives catalogue requests, not the selected source bytes.
The converter creates a separately named output. It never writes back into the source file.
One .tsv or .tab file up to 5 MB, limited to 50,001 rows, 200 columns, 1,000,000 cells, and a 20 MB generated workbook. Every row must have equal width.
Plain-language method
Nirmion parses quoted tabs, doubled quotes, and embedded line breaks, checks that every row has the same number of cells, writes all values as text into a new XLSX worksheet, and optionally styles and freezes the first row. It does not run formulas or infer dates.
Use UTF-8 TSV with literal tab separators. Quoted values may contain tabs or line breaks when their quotes are balanced.
Enable Header row when row one contains column names; disable it for headerless matrices. The worksheet name is cleaned to Excel limits.
The result ends in _nirmion_tools_workbook.xlsx. Text values, including leading zeroes, are less likely to change unexpectedly.
WORKED EXAMPLE / REVIEW BEFORE RELYING
Use a short, non-sensitive sample first. This example shows the checkpoints to apply before moving an authorised dataset into the destination workflow.
Choose sample.tsv with a header and two representative, non-sensitive records.
Keep the documented defaults, convert once, and compare the preview or result count with the TSV sample.
Open the separate Excel download and verify two records, field names, nulls, encoding, and destination compatibility.
Useful when
Before converting
Know the boundary
The converter deliberately avoids type guessing, formula creation, date parsing, and regional number conversion. Apply worksheet types only after reviewing the generated file.
Quick answers
Text-first writing protects source representation.
Cells are written as text, which reduces accidental changes to codes and identifiers.
Yes, when the source uses balanced CSV-style quotes around the field.
No. Each conversion creates one clearly bounded worksheet.