TSV to CSV Converter

No. Your TSV is never sent to our servers - all parsing, conversion, escaping, copy, and download happen directly in your browser on your device using JavaScript. The only network request the tool ever makes is the one you trigger explicitly with URL Import, which goes from your browser to the URL you enter.

Three: comma (the universal CSV default), semicolon (the European convention used when commas are decimal separators), and pipe (useful when your data contains both commas and semicolons). Pick from the Output dropdown next to the Convert button. The full RFC 4180 escaping rules are applied for whichever delimiter you choose.

Yes. The parser is full RFC 4180-style: a cell wrapped in double quotes can contain literal tabs, newlines, and embedded double quotes (escaped by doubling them). Spreadsheets like Excel and Google Sheets occasionally produce such cells when copying multiline content - the tool reads them correctly without splitting on the embedded tab.

Cell text is wrapped in double quotes whenever it contains the chosen output delimiter, a double quote, or a newline character. Embedded double quotes are escaped by doubling (""). Cells without those characters are written bare. This follows RFC 4180 so the output opens correctly in Excel, Google Sheets, LibreOffice Calc, Python's csv module, and any other CSV reader.

The Upload picker accepts .tsv, .txt, and .csv files. Drag-and-drop accepts the same. URL Import calls fetch() directly from your browser to the target URL - the URL must allow cross-origin requests via CORS headers. You can also type or paste TSV directly into the textarea.

Your settings (output delimiter) are saved to your browser's local storage under the key "tsv-to-csv-converter" and restored on the next visit. Your TSV input and generated CSV output are not saved - storing large files on every keystroke would slow the tool down. Re-paste, re-upload, or re-fetch your TSV after a refresh.

The tool is optimized for big files. The full CSV output is always generated and available via Copy and Download, but the on-screen displays are capped: the input textarea is limited to the first 500 lines and the CSV output preview is also limited to the first 500 lines. The full content is still in memory and used during conversion - the caps are display safeguards that keep the page responsive.

Yes, indirectly. Although the tool is named TSV to CSV, the parser is delimiter-aware enough that you can also paste regular CSV - the parser handles tabs and quoted cells. The output uses the delimiter you select. So pasting a comma-separated input and selecting Semicolon will give you a semicolon-separated output.

No. Cell values are written exactly as they appear in your input, with only the standard RFC 4180 quoting applied for safety. Empty cells stay empty, leading and trailing whitespace inside cells is preserved, and the row/column order matches the input. Short rows are not padded - the resulting CSV is exactly as wide as your widest row.

The TSV parser is hand-written and respects the RFC 4180 quoting rules. A cell wrapped in double quotes can contain literal tabs, embedded newlines, and escaped double quotes (doubled). CRLF and LF row terminators are both handled. This is a real parser, not a naive split('\t') - it correctly reads complex TSV exports from spreadsheets and databases.

Pick the output delimiter from the Output dropdown next to the Convert button. Comma is the universal CSV default and the most widely supported. Semicolon is the European convention used in locales where commas are decimal separators (e.g., 3,14 instead of 3.14). Pipe is useful when your data already contains both commas and semicolons and you need a third option that won't collide.

Cell values are wrapped in double quotes whenever they contain the chosen output delimiter, a double quote, or a newline. Embedded double quotes are escaped by doubling (""). Cells without those characters are written bare. The output opens cleanly in Excel, Google Sheets, LibreOffice Calc, Python's csv module, and any other CSV reader.

Four ways to load TSV data: type or paste straight into the textarea, click Upload to pick a .tsv / .txt / .csv file, drag a file onto the Input area, or click URL Import to reveal a URL field that calls fetch() directly from your browser to the target endpoint with no proxy. URL Import requires the target server to allow cross-origin requests via CORS headers.

When you load a large TSV file, only the first 500 lines are written to the input textarea. The full file is still stored in memory and used during conversion - the cap is purely a display safeguard to keep the page responsive when the source is multi-megabyte. A notice next to the Input label tells you when the preview is limited.

The output panel shows the generated CSV in a read-only text area so you can read and inspect the data. For huge tables the displayed text is limited to the first 500 lines and a notice next to the Output label tells you the preview is limited. Copy and Download always work on the full output - the cap is purely a display safeguard to keep the page responsive when the generated CSV is megabytes long.

After conversion, a status line in the output toolbar shows the exact number of rows and columns extracted from the TSV. This is useful for sanity-checking before you copy or download - if the count looks wrong, the source file may be malformed or you may have selected the wrong delimiter.

When you load a file or fetch a URL, a spinner overlay appears over the Input area with a status message. When you click Convert to CSV, a spinner overlay appears over the Output area until the conversion finishes. This makes it obvious when the tool is working on something rather than appearing frozen.

Click Copy CSV to copy the entire generated output to your clipboard via navigator.clipboard.writeText(). The button label briefly changes to "Copied!" for 1.5 seconds as confirmation, then reverts.

Click Download CSV to save the output as a converted.csv file. The blob is created locally on your device and the temporary object URL is released after the download is triggered.

Your output delimiter setting is saved to your browser's localStorage under the key "tsv-to-csv-converter" and restored on the next visit. Your TSV input and generated CSV output are intentionally not saved - they can be very large, and persisting them on every keystroke would slow the tool down. Re-paste, re-upload, or re-fetch your TSV after a refresh.

Click Clear to wipe the input textarea, the generated CSV, the row stats, the URL Import bar, and any error message in a single action. Your saved settings are kept so you do not have to reconfigure the output delimiter when starting a new conversion.