Convert TSV to CSV Tab to comma, correctly.

Q: How do I convert TSV to CSV in Python?

import pandas as pd; df = pd.read_csv('file.tsv', sep=' '); df.to_csv('output.csv', index=False). Or with the csv module: csv.writer(open('out.csv','w')).writerows(csv.reader(open('in.tsv'), delimiter=' ')).

Q: How do I open a TSV file in Excel?

Excel opens .txt and .tsv files with the Text Import Wizard when double-clicked — set delimiter to Tab. Or convert the TSV to CSV using CSVShift first, then open the .csv file directly in Excel without any wizard.

TSV to CSV Converter 100% client-side

Drop your TSV file here

.tsv, .tab, .txt — or paste tab-separated data below

or paste tab-separated data directly

Input delimiter

Output delimiter

Output quoting

Conversion complete

What the conversion does to your data

The critical change: fields containing commas get quoted in the CSV output.

Example — city names with commas

TSV input (tab-separated)

name	age	city
Alice	32	New York, NY
Bob	28	Paris, France
Carol	29	Austin, TX

→

CSV output (correctly quoted)

name,age,city
Alice,32,"New York, NY"
Bob,28,"Paris, France"
Carol,29,"Austin, TX"

The city values did not need quoting in TSV — commas are ordinary characters when the delimiter is a tab. But in CSV, any field containing a comma must be wrapped in double quotes to prevent the comma from being interpreted as a column separator. CSVShift adds these quotes automatically.

How TSV to CSV conversion works

Parse, evaluate, re-serialise — not find-and-replace.

Parse tab-delimited fields

The TSV is parsed field by field, tracking quoted regions. Fields in TSV can be quoted when they contain embedded tabs or newlines — these are decoded correctly, stripping the outer quotes and unescaping any "" sequences inside.

Evaluate each field for CSV quoting

Each decoded field value is checked against the RFC 4180 CSV quoting rules: does it contain a comma (the output delimiter), a double quote, a newline or a carriage return? If yes, it must be quoted in the CSV output. In minimal mode, only fields that require quoting get quotes — keeping the output clean.

Re-serialise as valid CSV

Fields are joined with commas, quoted fields use "...", embedded quotes are escaped as "". The result is RFC 4180 compliant CSV that opens correctly in Excel, Google Sheets, pandas and any other CSV parser.

TSV to CSV — code examples

For scripting and automation workflows.

Python — pandas

import pandas as pd # TSV to CSV: df = pd.read_csv('data.tsv', sep='\t') df.to_csv('output.csv', index=False) # With explicit encoding: df = pd.read_csv('data.tsv', sep='\t', encoding='utf-8') df.to_csv('output.csv', index=False, encoding='utf-8-sig') # UTF-8 BOM for Excel

utf-8-sig adds the UTF-8 BOM — recommended when the output will be opened in Excel to ensure accented characters display correctly.

Python — csv module (no dependencies)

import csv with open('data.tsv', newline='', encoding='utf-8') as fin, \ open('output.csv', 'w', newline='', encoding='utf-8') as fout: reader = csv.reader(fin, delimiter='\t') writer = csv.writer(fout) # default delimiter=',' writer.writerows(reader)

csv.writer automatically quotes fields that contain commas, newlines or quotes. This is the correct, portable approach — do NOT use sed or awk.

Command line — safe Python one-liner

# TSV → CSV (handles quoted commas correctly): python3 -c " import csv, sys r = csv.reader(sys.stdin, delimiter='\t') w = csv.writer(sys.stdout) [w.writerow(row) for row in r] " < input.tsv > output.csv # Or using sed (ONLY for TSV with no commas in values): sed 's/\t/,/g' input.tsv > output.csv

The sed approach breaks if any field value contains a comma. The Python one-liner is always correct — use it unless you are certain no values contain commas.

When do you need to convert TSV to CSV?

Common workflows where TSV data needs to become standard CSV.

Database and tool exports

MySQL CLI, psql, SQLite and many data tools output tab-separated data by default when piping to the terminal. Converting this output to CSV makes it compatible with spreadsheet tools and CSV-expecting import functions.

Paste from Excel or Google Sheets

When you copy cells from Excel or Google Sheets and paste into a text editor, the data arrives as tab-separated values. Converting to CSV produces a proper file with consistent quoting that any downstream tool can parse.

Bioinformatics and scientific data

Many scientific data formats (UCSC Genome Browser, GTEx, GEO) distribute data as TSV or TXT files with tab delimiters. Converting to CSV enables use with tools that only accept comma-separated input.

CRM and SaaS imports

Salesforce, HubSpot, Mailchimp and most SaaS platforms require CSV imports, not TSV. When your data source exports as TSV, converting to CSV is the mandatory step before importing contact lists, product catalogs or records.

Related CSV tools

Other free converters on CSVShift you might need.

TSV to CSV conversion
done correctly.

The naive approach — replacing every tab with a comma — breaks the moment a field value contains a comma. CSVShift fully parses the tab-delimited input, extracting each field value correctly, then evaluates which fields need quoting in the CSV output and serialises accordingly.

This is the same parse-then-reserialise approach used by Python's csv module and pandas. The output passes validation by any RFC 4180 compliant CSV parser including Excel, Google Sheets, PostgreSQL COPY and MySQL LOAD DATA INFILE.

Automatic comma quoting

Fields containing commas are automatically wrapped in double quotes — the RFC 4180 requirement for valid CSV.

Full TSV parser

Correctly decodes quoted TSV fields with embedded tabs, newlines and escaped double quotes.

Upload or paste

Drop a .tsv file or paste tab-separated data directly — both paths use the same correct parser.

Free, no conditions

No file size limit, no row cap, no watermark. Funded by display advertising only.

Frequently asked questions

Common questions about converting TSV files to CSV format.

How do I convert TSV to CSV?

Upload your .tsv file or paste tab-separated data into CSVShift and click Convert. Fields that contain commas are automatically quoted in the CSV output. Download the .csv file or copy to clipboard.

How do I convert TSV to CSV in Python?

With pandas: pd.read_csv('f.tsv', sep='\t').to_csv('out.csv', index=False). With the csv module: csv.writer(open('out.csv','w')).writerows(csv.reader(open('in.tsv'), delimiter='\t')). Both correctly quote fields that contain commas. Do NOT use sed 's/\t/,/g' — it breaks values containing commas.

How do I open a TSV file in Excel?

Two approaches: 1) Convert to CSV here first, then open the .csv directly in Excel without any wizard. 2) In Excel, open the .tsv file directly — Excel launches the Text Import Wizard, set delimiter to Tab. The first approach is simpler and avoids the wizard.

Why does my TSV have fields with commas and will they break my CSV?

Fields containing commas in TSV are perfectly valid — commas are ordinary characters when the delimiter is a tab. When converting to CSV, CSVShift automatically wraps these fields in double quotes so the comma is not interpreted as a column separator. The output is valid RFC 4180 CSV that parses correctly in any tool.

Is my data safe when converting TSV to CSV online?

Yes. The entire conversion runs in your browser in JavaScript. Your file is never uploaded to any server. Open the Network inspector during conversion — zero outbound data requests are made.

Convert TSV to CSVTab to comma,correctly.

TSV to CSV conversiondone correctly.

Convert TSV to CSV
Tab to comma,
correctly.

TSV to CSV conversion
done correctly.