TSV to CSV Converter

What this tool is used for

• Converting a tab-separated export for a tool that only reads CSV.
• Turning pasted spreadsheet data into a comma-separated file.
• Converting a file whose values contain commas, so the quoting has to be added.
• Converting a file for an importer that cannot be configured.
• Preparing data for a tool whose CSV parser is stricter than its TSV one.

Frequently Asked Questions

Why is TSV sometimes better than CSV?

Because tabs are far rarer in real data than commas, so quoting is rarely needed and parsing is simpler. That is why bioinformatics and many database exports prefer it — fewer escaping edge cases.

What breaks converting TSV to CSV?

Any field containing a comma. In TSV it needed no quoting; in CSV it must be wrapped in double quotes per RFC 4180, and internal quotes doubled. A naive tab-to-comma replacement silently corrupts those rows.

How are embedded tabs and newlines handled?

TSV has no official escaping mechanism, which is its real weakness — a field containing a tab is simply ambiguous. Most producers replace them with \t or spaces, so the data was already altered upstream.

Does Excel handle these the same way?

No, and it is a common frustration. Excel's CSV delimiter follows your system's list separator, so a semicolon is used in many European locales. TSV pastes more reliably into a spreadsheet than CSV does.

Which should I use for interchange?

CSV for broad compatibility, since everything reads it. TSV when your data contains commas and you control both ends. For anything with embedded newlines or quotes, a real format like JSON or Parquet is a better answer.

How is a leading zero preserved through the conversion?

It is not, by the format — both are plain text and neither carries types. The loss happens in the spreadsheet that opens the file, which is why importing as text rather than double-clicking is the actual fix.

Which is safer for data containing free text?

TSV, marginally — tabs are far rarer inside prose than commas, so fewer fields need quoting. That is why bioinformatics and log formats favour it, and why a naive splitter fails less often on TSV.

Common errors and gotchas

• Not quoting values that contain commas, which the tab format never needed to quote.
• Losing values that contain quotes, which now need escaping where before they did not.
• Overlooking embedded newlines, which break a line-based conversion in either direction.
• Assuming the tab format had no quoting rules, when some producers do quote.
• Letting a spreadsheet reinterpret the result, turning codes into dates and dropping leading zeros.