How to Open a Tab-Delimiter CSV in Excel (TSV Files)

To open a tab-delimiter CSV in Excel, use Data > From Text/CSV and set the delimiter to Tab — or use the Text Import Wizard with Tab ticked. A tab-delimiter file (usually saved with a .tsv extension) separates values with tab characters instead of commas. If Excel opens it with the wrong delimiter, every row collapses into a single column, and the file looks broken. It is not broken: Excel just needs to be told to split on tabs.

TSV files show up in specific places: exports from databases and data tools, bioinformatics and research datasets, logs, and systems that allow commas inside values (addresses, product descriptions) and therefore cannot safely use commas as separators. (For an ordinary comma-separated file, the free CSV to Excel converter converts it in one step.) The fix is the same in every case — import with Tab as the delimiter — but the details matter, because a TSV with quoted fields or mixed line endings can still misbehave. This guide covers the import, the common pile-up problem, and the edge cases.

What a TSV File Actually Is

A TSV (tab-separated values) file is a CSV with a different separator. Each line is a row, and within a line, a tab character separates one field from the next. Commas inside a value are harmless in TSV, which is exactly why tools that export free-text fields prefer it: a product description containing "red, large, cotton" stays one field in TSV, while in CSV it needs quoting to survive.

The catch is the file extension. A .tsv file double-clicked in Windows may open in a text editor instead of Excel, and a .csv file that is actually tab-separated will open in Excel — with every row crammed into column A. Both symptoms have the same cause: the program guessed the wrong delimiter. The reliable fix is to import deliberately rather than double-click.

Method 1: Data > From Text/CSV (Recommended)

This is the modern import path and the one to use by default.

1. Open Excel to a blank workbook. Go to Data > From Text/CSV.
2. Select your file. Pick the .tsv file (change the file filter to "All Files" if it is hidden) or a .csv file you know is tab-separated.
3. Set the delimiter. In the preview dialog, change Delimiter to Tab. The preview should instantly split into proper columns. If it does not, the file may use a different separator — check the raw text first (see "Diagnosing the File" below).
4. Check the encoding. Set File Origin to UTF-8 (65001) unless the preview shows garbled accents. If accented characters look wrong, try the encoding your source system uses; the guide to fixing CSV encoding errors in Excel explains the symptoms.
5. Load. Click Load. Save the result as .xlsx (File > Save As) so formatting, filters, and any fixes survive.

Method 2: Text Import Wizard (Best for Control)

The older wizard gives more control over column types — useful when a TSV contains code columns with leading zeros, long IDs, or dates in a non-default format.

1. Go to Data > Get Data > Legacy Wizards > From Text (Legacy). If the legacy option is missing, enable it under File > Options > Data > "Show legacy data import wizards".
2. Select the file. In step 1, choose Delimited and the correct file origin.
3. In step 2, tick Tab and untick everything else. The preview should split into columns.
4. In step 3, click each column in the preview and set its type: General for most, Text for codes/IDs with leading zeros, Date with the right DMY/MDY order for date columns. Setting a code column to Text is the reliable way to keep leading zeros — the same rule as for semicolon-delimiter CSVs.
5. Click Finish, choose where to place the data, and save as .xlsx.

The Single-Column Pile-Up (and How to Undo It)

If you already double-clicked a TSV and everything landed in column A, you do not need to re-import. Excel can split it in place:

1. Select column A (click the column header).
2. Go to Data > Text to Columns. Choose Delimited > Next.
3. Tick Tab only, untick Comma and everything else. Click Next.
4. Set column types (Text for code columns), click Finish.

The single column splits into the full table. This works for a file already open; for a fresh file, Method 1 is cleaner because it also handles encoding.

One warning: Text to Columns overwrites the columns to the right of the selection. If column B already holds data, insert a few blank columns first or work on a copy.

Diagnosing the File Before You Import

If Tab does not split the preview, the file may not be what you think. Open it in a plain text editor (Notepad, TextEdit in plain-text mode, VS Code) and look at the raw text:

• Tabs visible as wide gaps between values, with no commas doing the separating → it is TSV; Tab is the right delimiter.
• Commas between values → it is an ordinary CSV, and Comma is the delimiter. (Use the standard CSV import.)
• Semicolons → it is a European-style CSV; see the semicolon-delimiter guide.
• **Pipe characters (|)** → it is a pipe-delimited file; see the pipe-delimiter guide.
• No visible separator at all → the file may use fixed-width columns, or its line breaks may be missing. Fixed-width files need the Fixed Width option in the wizard, not a delimiter.

Also check line endings: a file saved on an old Mac may use carriage returns alone, which Excel can misread as one giant line. If the whole file appears as a single row, re-save it with standard line endings in a text editor, or import via Power Query, which handles mixed line endings more gracefully.

TSV vs CSV at a Glance

Edge Cases Worth Knowing

Tabs inside a value. A description field containing a literal tab will split mid-value. If a row has more columns than the header, a stray tab is the likely cause. Fix it in the source system (replace tabs in text fields with spaces before export), or merge the split cells by hand for the few affected rows.

Quoted fields. Some TSV exporters wrap fields in double quotes. Excel's import handles standard quoting, but a quote character inside an unquoted field can confuse it. If one row misbehaves while the rest are fine, inspect that row's raw text for a stray quote.

Very large TSV files. Files over a million rows exceed a worksheet's limit. Import with Power Query (Data > Get Data > From File > From Text/CSV) and load to the Data Model, or split the file first — the guide to splitting a CSV into multiple Excel sheets by column covers the splitting approach.

Saving back to TSV. If another system needs TSV back, save as Text (Tab delimited) (*.txt) from Excel, not as CSV. Saving as CSV would silently change the separator and break the downstream import.

FAQ

What is a TSV file?

A TSV (tab-separated values) file is a plain-text table where a tab character separates the fields in each row — the same idea as a CSV, but with tabs instead of commas. It is common in database exports, research datasets, and systems whose text fields contain commas.

Why does my TSV open in one column in Excel?

Because Excel guessed the wrong delimiter. It split on commas, found none, and put each whole row into a single cell. Re-import with Data > From Text/CSV and Tab as the delimiter, or fix the open sheet with Data > Text to Columns > Tab.

How do I convert TSV to Excel?

Import the TSV with Tab as the delimiter (Data > From Text/CSV), then save as .xlsx. That gives you a real workbook with formatting, filters, and formulas. Do not just rename the file to .xlsx — renaming changes the label, not the format, and Excel will still treat it as text.

How do I save Excel back as TSV?

Use File > Save As > Text (Tab delimited) (*.txt). Excel warns that formatting will be lost — that is expected, since TSV stores text only. Keep the .xlsx as your master and export the TSV as a copy.

Can a TSV contain commas?

Yes — that is the point of TSV. Commas inside a value are harmless because the tab is the separator. What TSV cannot contain is a literal tab inside a value; that would split the field. Replace tabs in text fields with spaces before exporting.

Final Checklist

• Imported with Tab as the delimiter (not double-clicked and hoped).
• Preview showed proper columns before loading.
• Encoding set so accents and special characters display correctly.
• Code/ID columns set to Text so leading zeros survive.
• File saved as .xlsx; TSV exported separately only if another system needs it.

If all five checks pass, your tab-delimited file is now a clean Excel table — every value in its own column, nothing lost in the pile-up.