CSV to TSV Converter

This tool converts CSV (comma-separated values) to TSV (tab-separated values) in your browser. The data is parsed locally; nothing leaves your machine. For the inverse direction, see TSV to CSV.

CSV vs TSV

The two formats are near-identical. The differences:

When you copy from a spreadsheet (Excel, Google Sheets, Numbers) and paste into a text editor, you usually get TSV. CSV is the file-format default; TSV is the clipboard default.

The conversion

For CSV without quoted values, the conversion is “replace , with \t”:

CSV: name,age,city
TSV: name<TAB>age<TAB>city

For CSV with quoted values, the conversion has to:

1. Parse the CSV correctly (respecting quotes and escapes).
2. Re-emit each cell as TSV.

CSV: Alice,"NYC, NY",30
TSV: Alice<TAB>NYC, NY<TAB>30

The comma in NYC, NY is now safely a literal — TSV doesn’t use comma as a delimiter, so no quoting is needed for it. The conversion strips the surrounding quotes that CSV required.

Tabs inside values

The single thing TSV doesn’t handle gracefully is tabs inside values. If a CSV cell contains a tab character (rare but possible), naively converting to TSV produces an extra delimiter:

CSV cell: "first\tsecond" (one cell with a tab inside)
Naive TSV: first<TAB>second  ← parses as TWO cells

The IANA TSV spec forbids tabs inside fields; there’s no standard escape mechanism. Workarounds:

• Replace internal tabs with spaces (lossy but most common).
• Replace internal tabs with \t literal (unambiguous but the consumer needs to un-escape).
• Use a different format (CSV, JSON, or a delimited-format with a richer escaping layer).

The tool above replaces internal tabs — and newlines inside quoted cells — with spaces, without a warning. If preserving them matters, stay in CSV or use JSON.

Newlines inside values

Both CSV and TSV face the same problem: a newline inside a cell looks like a row terminator. CSV’s RFC 4180 says wrap the cell in quotes and the parser tracks state; TSV has no analogous mechanism in the bare spec. Some TSV parsers extend with quote support; many don’t.

Practical advice: if your data has newlines in cells, prefer CSV (with quoting) or JSON. TSV’s lack of standard escaping makes it the wrong format for these.

When TSV is the right format

• Pasting data from a spreadsheet into a tab-supporting tool (most code editors, GitHub issue text boxes, Notion).
• Unix shell pipelines. cut, awk, sort, join all handle TSV more gracefully than CSV (no quote-state to track).
• Bioinformatics. Most bioinformatics file formats (BED, GFF, VCF, MAF) use tab separation. The community defaults to TSV.
• Quick interchange between tools that both speak TSV. Less spec ambiguity than CSV.

When CSV is better

• Files going to or from Excel as files (not via copy-paste). Excel’s CSV import is well-trodden; its TSV import requires telling Excel the delimiter.
• Data with internal commas, quotes, or newlines. CSV’s RFC 4180 quoting handles these; TSV’s spec doesn’t.
• Public data interchange. CSV is more widely understood; TSV requires more explanation.

Common pitfalls

• Visible whitespace ambiguity. Tabs render as varying widths in different editors. A column-aligned-looking TSV file may have inconsistent tabs that break parsers. Use a editor that visualizes whitespace when troubleshooting.
• Mixing CSV and TSV in one file. A “CSV” file with some tab-separated rows and some comma-separated is corrupt. Pick one delimiter per file.
• Trailing tabs. A row ending in \t adds an extra empty cell. Some parsers trim; some don’t. Most spreadsheets export TSV with no trailing tab.
• Excel locale issues. Excel in some locales (Germany, France) uses ; as the CSV delimiter and , as the decimal separator. “CSV” in those exports isn’t comma-separated. Detect the actual delimiter before parsing.
• Encoding. TSV doesn’t specify encoding; UTF-8 is the modern default. Older TSV files may be Latin-1 or Windows-1252.

For other format conversions, see CSV to JSON, TSV to CSV, CSV to Markdown table.