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TSV to CSV
Paste tab-separated text or drop a .tsv file and download it as CSV. It is not a find-and-replace:
a value that already contains a comma, a double quote or a line break is quoted the way RFC 4180
says, so Desk, oak stays one cell instead of becoming two. The count of cells that needed
quoting is shown. Output can use commas or semicolons, the encoding is detected, and values such as
00042 are copied exactly. Nothing is uploaded.
Your .tsv file
Drop a .tsv or .txt file here, or click to choose
…or paste tab-separated text copied from Excel or a database client
Doing this every month? Do it once in TableDI 2, save it as a job, and run it again next month. Download TableDI 2 free
Nothing is uploaded. The file is read by JavaScript in this tab and never leaves your computer — no server sees it, and closing the tab throws it away.
How to convert TSV to CSV without breaking values
- Load the TSV. Drop the file or paste the text. Tabs are recognized as the delimiter; the encoding is detected for files.
- Pick the output delimiter. Comma for most tools; semicolon if the file will be opened by Excel set to a European locale.
- Check the counts. How many cells needed quotes, and a warning if rows have different numbers of columns — usually a stray tab inside a value.
- Download or copy. The CSV is UTF-8; tick the BOM option if it will be opened by double-clicking in Excel on Windows.
Why replacing tabs with commas breaks the file
TSV and CSV look like the same format with a different separator. They are not, because they treat
special characters differently. A
TSV
file simply may not contain a tab inside a value, so commas and quotes inside values need no protection.
CSV (RFC 4180) protects them with
double quotes. Swap the separators with a text editor and Desk, oak, 140 cm becomes three
cells; Chair "Aeron" becomes a parse error in the next program.
This page parses the TSV into cells first and then writes real CSV: values containing the output delimiter, a double quote, a line break or leading and trailing spaces are wrapped in quotes, and quotes inside them are doubled. The number of cells that needed it is shown, so you know whether a naive conversion would have been wrong.
Comma or semicolon
Where the decimal separator is a comma — Germany, France, Spain, Italy, Brazil and most of Europe — Excel expects CSV files to use a semicolon and puts a comma-separated file entirely into column A. Pick the semicolon if that is who opens the file. The numbers themselves are copied exactly as they were; nothing is reformatted.
Why not just open it in Excel and save as CSV
Because Excel interprets every value on the way in. 00042 becomes 42, a
16-digit order number loses its last digits, and 3-4 may turn into a date. Save as CSV
afterwards and the damage is in the file. Here the values are never treated as numbers or dates; the
output has the same characters as the input.
Encoding
A dropped file is decoded by detection (UTF-8, UTF-16, Windows-1252 and others), and the encoding that was used is shown under the counts. The CSV is always written as UTF-8. Excel on Windows needs a byte-order mark to read UTF-8 accents correctly when the file is opened by double-click; tick the BOM option for that case and leave it off for scripts and databases.
When the same export has to be converted every period
TableDI 2 is a desktop app for file work you redo every period: it keeps your sources, rules and delivery as a job, so next month you drop in the new files and run it again. Everything runs on your own machine.
Questions people ask
What is the difference between TSV and CSV?
Both store one record per line. TSV separates values with a tab and does not allow tabs inside values; CSV separates them with a comma (or a semicolon in many European locales) and protects commas, quotes and line breaks inside values with double quotes, as RFC 4180 describes.
Can I just replace the tabs with commas?
Only if no value contains a comma, a double quote or a line break. Any that does is split into extra columns or breaks the parser. This page quotes those values and shows how many there were.
Will leading zeros and long numbers survive?
Yes. Values are copied character for character — 00042 stays 00042. They are
lost only when a spreadsheet program opens the CSV and reinterprets them, which is a property of that
program, not of the file.
Can it convert CSV to TSV?
Not on this page; the output delimiter can be a comma, a semicolon or a pipe. For a table view of either format, use the CSV viewer.
Are my files uploaded anywhere?
No. The file is read by JavaScript running in this tab, using the browser's own
DecompressionStream to unzip .xlsx and a parser that runs on your machine. The page does load two visitor counters — static.cloudflareinsights.com and this site's own /_vercel/insights — but no request carrying your data appears in the network tab while you use it. Close the tab and the data is gone.
Related
Doing this every month?
In TableDI 2 you do it once, then save it as a job. Next month you drop in the new files and run it again.
macOS, Apple silicon and Intel; Windows is in progress (what to do meanwhile). Free is not a trial — no account, no card.
Last reviewed 2026-10-01 by the TableDI team. Something wrong on this page? Tell us — it is one inbox, read by the people who build TableDI.