TSV to CSV

Tab-separated text is everywhere, often without a name. When you copy cells from Excel or Google Sheets, the clipboard holds TSV. Database tools export it, scientific software in genomics and bioinformatics writes it, and Excel’s “Unicode Text” export is UTF-16 TSV. Yet many import forms and tools accept only comma-separated CSV or Excel files. This tool converts tab-separated data into either.

Getting the data in

Drop a .tsv, .tab or .txt file, or simply paste cells you copied from a spreadsheet into the paste box. The tab separator is recognized automatically, and so is the text encoding, including UTF-16 files written by Excel. CSV and Excel files are accepted too, so the same page also converts in the other direction.

Quotes and special characters

Most TSV files have no quotes, because tabs rarely occur inside text. When a value does contain a tab or a line break, well-formed files wrap it in double quotes, and those values are read correctly. In the CSV output, values that contain the new separator, a quote or a line break are quoted, exactly as the CSV standard requires, so columns never shift.

Invisible tabs

Tabs are invisible, which makes TSV fragile: one stray tab typed into a note silently adds a column and pushes the rest of the row to the right. The preview shows the parsed table with row numbers, so such rows stand out before you convert. Fix them in the source, or remove the stray characters with CSV Find and Replace.

Choosing the output

CSV is the most widely accepted format; pick comma or semicolon to match the program that will read it, and add a byte order mark if Excel will open the file. Excel output creates a workbook with a bold, frozen header row, where plain numbers and ISO dates become real values and codes with leading zeros stay text. TSV output re-saves the data cleanly as tab-separated text.

Values are not changed

Every cell is copied exactly: leading zeros in sample IDs, gene names that Excel likes to turn into dates such as MARCH1 or SEPT2, long accession numbers and decimal values all arrive as written.

Typical sources

Clipboard copies from spreadsheets, exports from SQL clients and database dumps, Excel’s Unicode Text, BLAST and other bioinformatics outputs, analytics exports and machine logs.

Converting CSV to TSV

The same page works in reverse: drop a CSV or Excel file and choose TSV as the output. TSV is handy for pasting into spreadsheets and for tools in data science and bioinformatics that expect tabs.

Large files

Tab-separated exports from databases and analysis pipelines can be large. Conversion happens in your browser’s memory, so files of a few hundred megabytes work on a computer, while a phone is best kept to smaller files.

Privacy

The data is converted on your device and never uploaded, which matters for research data and customer exports alike.

Related tools

To switch a CSV between comma, semicolon, tab and pipe, use Change CSV Delimiter. For column-aligned text with spaces instead of tabs, use Fixed-Width to CSV. To open any CSV as a workbook, see CSV to Excel.