TSV to CSV Converter

Tab-separated files turn up whenever something exports a quick table without thinking about CSV rules: a copy-paste straight out of a spreadsheet, a database client's "export as text", a log dump, or a scientific or analytics tool that defaults to tabs. The trouble starts downstream, because plenty of importers, BI tools, and older line-of-business systems expect commas and quietly mishandle or reject tabs. This converter exists for exactly that handoff moment: you have clean tab-delimited rows and you need standard CSV the next tool will accept.

Concrete fits include standardising tab-separated exports before loading them into a system that only reads CSV, prepping a column for a mail-merge or a CRM import, handing a colleague a file that opens predictably in their spreadsheet, or normalising a batch of mixed exports so a script can treat them uniformly. It is equally handy for a student or admin who pasted a table out of one app and needs it in the format another app documents as required.

It is a format-shape tool, not a data-cleaning suite. It changes the delimiter and applies correct quoting; it does not reorganise columns, deduplicate, fix typos, or interpret meaning. If your only obstacle between two tools is "this one speaks tabs, that one speaks commas", this is the right size of tool for the job.

The flow is direct: paste your TSV or load a file in the browser, the conversion runs locally, and you copy the result or download it as a .csv. Everything happens in your own browser tab. Nothing is uploaded to a server, and nothing is retained once you close the tab.

Under the hood the tool reads your input character by character, splitting rows on tabs while honouring quotes. A field wrapped in double quotes can contain tabs, line breaks, or doubled quotes ("") without being split, and both LF and CRLF line endings are recognised. On output it writes commas between fields and quotes a cell only when it needs to: if the value contains a comma, a double quote, or a line break, it is wrapped in quotes and any internal quotes are doubled. That is the minimal-quoting behaviour most CSV readers expect, so a cell like Smith, John survives the round trip intact. Output rows are joined with LF newlines.

What it does not do is also worth stating plainly. It does not change character encoding, infer or preserve number versus text types, validate that every row has the same column count, or strip a byte-order mark for you. It treats the content as text and reshapes the delimiters; the values themselves pass through unchanged.

The most common surprise is input that was never truly tab-separated. If a source used multiple spaces for alignment rather than real tab characters, the parser will see one wide column instead of several, because it splits strictly on the tab character. Ragged rows are another trap: the tool will not pad or warn about rows with fewer or more fields than the header, so a stray tab inside an unquoted cell silently shifts everything after it.

Encoding is the second thing to watch. Because the converter does not transcode, a file saved as Latin-1 or with an unexpected BOM can carry those quirks straight into the CSV, where accented characters or a leading invisible mark may show up wrong in the receiving program. Very large inputs are processed entirely in memory in the tab, so an extremely big file can strain the browser before it strains anything else.

Finally, remember CSV has no single dialect. This tool produces comma-delimited, LF-terminated output with standard double-quote escaping. If your destination specifically wants semicolons, CRLF endings, or a particular text encoding, you may need a follow-up step or a tool tuned for that target.

Open the CSV and confirm the column count matches your source on a few representative rows, especially the first row and any rows you know contain commas, quotes, or free-text notes. Verify that cells which originally held commas are now wrapped in quotes, that doubled quotes read back correctly, and that nothing collapsed into a single column, which is the tell-tale sign the input was space-aligned rather than tab-separated. Spot-check any accented or non-Latin characters to catch an encoding mismatch the converter cannot fix on its own.

It also helps to load the output into the actual program you are targeting rather than judging it by eye, since that is the real test of whether the dialect and quoting suit it. Check the header row landed as a header and that numeric-looking values are interpreted the way you need; the tool preserves them as text, and any type handling happens in the destination.

For anything official, financial, or legal, do a manual line-by-line verification against the source rather than assuming the conversion is faithful. Confirm row counts, totals, identifiers, and any field where a misplaced delimiter would change the meaning, and keep the original TSV as the authoritative record.