Same tabular data, different delimiter. CSV separates fields with commas; TSV separates them with tabs. These two tools swap one for the other — nothing more, nothing less. Pick by which delimiter your destination expects.

Use CSV → TSV when

  • A tool or pipeline expects tab-separated input but you have a CSV file.
  • Your fields contain commas, and tabs would avoid the quoting headaches.
  • You're moving a spreadsheet export into a TSV-based system.

Use TSV → CSV when

  • A tool or spreadsheet expects comma-separated input but you have TSV.
  • You need the more universally recognized CSV format.
  • You're preparing tab-separated data for a CSV-based import.

Side by side

CSV → TSVTSV → CSV
DirectionCSV → TSVTSV → CSV
Input delimiterCommaTab
Output delimiterTabComma
Header row preserved?YesYes
Quoted fields handled?Yes — RFC 4180 parsingYes — RFC 4180 output
Runs 100% locallyYesYes
under the hood

One honest caveat: CSV → TSV is the lossy direction if a field contains an embedded newline — TSV can't keep it in one cell, so the converter refuses by default (with an escape option). TSV → CSV is always lossless because CSV quoting can hold anything.

bottom line

They're the same operation pointed in opposite directions — use whichever matches the direction you're converting. If your data has commas in fields, TSV is often the calmer format; if you need broad compatibility, CSV is the safer destination.