What is a comma-separated value (CSV)?

A comma-separated value (CSV) is a text format where each data item is separated by a comma. For example, 'apple, banana, cherry' is a comma-separated list of three items. CSV files are widely used for spreadsheet data, database imports/exports, API responses, and data pipelines because they are plain text and readable by almost every application.

How do I convert comma-separated values to a list?

Paste your comma-separated text into the Input box and select the 'Comma-separated → lines' mode. The tool splits on each comma and places each item on its own line, trimming extra spaces. This is useful for turning a CSV row into a vertical list for further editing or processing.

Can I use a custom delimiter instead of a comma?

Yes. Select the 'Custom separator' mode and enter your split character in the 'Split by' field (e.g., semicolon ; or pipe | or tab \t) and your join character in the 'Join with' field. You can also enable the RegEx checkbox to use regular expression patterns for splitting, which allows you to split on multiple characters or patterns at once.

What is the difference between a comma separator and a thousand separator?

A thousand separator (also called a thousands separator or grouping separator) is a comma placed every three digits in a large number to improve readability — for example, 1,000,000 instead of 1000000. A comma separator in the context of data refers to commas used to delimit items in a list or CSV file — for example, 'name, age, city'. This tool handles both uses: it can format numbers with thousand-separator commas and also manipulate comma-delimited lists.

Does this tool store or transmit my data?

No. All processing happens entirely in your browser using JavaScript. No data you enter is sent to any server, stored, or logged. The tool works offline once the page has loaded, making it safe to use with sensitive or confidential data.

How do I remove all commas from text?

Paste your text into the Input box and select the 'Remove commas from numbers' mode. This will strip every comma character from the input. For example, 1,234,567 becomes 1234567, and 'apple, banana, cherry' becomes 'apple banana cherry'. If you want to replace commas with a different character (like a space or semicolon), use the Find & Replace tab.

What number formatting convention uses commas?

The comma-as-thousands-separator convention is standard in the United States, United Kingdom, Australia, Canada, China, Japan, and many other countries. For example: 1,000 (one thousand), 1,000,000 (one million). In contrast, many European countries (Germany, France, Spain, Italy) use a period as the thousands separator and a comma as the decimal separator, so one million is written as 1.000.000 in those locales.

Comma Separator - Separate Text with Commas

Input

0 chars · 0 lines Live mode

Modes

Output

Chars

Lines

Items

Commas

History

Last 20 conversions

No conversions yet.

Quick Actions

Tips

💡 Use Add commas to format plain numbers like

→


         1,000

→


         2,500,000

📋 Use Lines → CSV to convert a vertical list into a single comma-separated line for spreadsheets.

⚙️ Use Custom separator to split on semicolons, pipes, or tabs and rejoin with any delimiter.

🔁 Click Use as Input to chain multiple transformations on the same text.

📂 Upload a


         .csv


         .txt

file directly to process large datasets.

Quick Reference

Add commas

Formats numbers with thousand separators. 1000000 → 1,000,000

Lines → CSV

Joins one-item-per-line into a comma-separated string.

CSV → Lines

Splits a comma-separated string into individual lines.

Custom separator

Split on ;|\t or RegEx and rejoin with any character.

Live Examples — What This Tool Does

Here are concrete before-and-after examples for every mode available in the Comma Separator Tool.

Add Commas to Numbers (Thousand Separator Formatting)

Number → Formatted Number 1000 → 1,000

2500000 → 2,500,000

1234567.89 → 1,234,567.89

-9876543 → -9,876,543

Remove Commas

Formatted Number → Plain Number 1,234,567 → 1234567

apple, banana, cherry → apple banana cherry

Lines → Comma-Separated

Vertical List → CSV String apple
banana
cherry → apple, banana, cherry

John
Jane
Bob → John, Jane, Bob

Comma-Separated → Lines

CSV String → Vertical List red, green, blue → red
green
blue

Spaces → Commas

Space-Separated → CSV foo bar baz qux → foo, bar, baz, qux

Custom Separator

Split on

→ Join with

a;b;c;d → a, b, c, d

Split on

→ Join with

name|age|city → name, age, city

When to Use a Comma Separator Tool — Real-World Use Cases

A comma separator tool is useful for developers, data analysts, writers, marketers, and anyone who works with lists, numbers, or tabular data. Here are the most common real-world scenarios.

📊 Spreadsheet Data Preparation

Convert a vertical list of values (one per line) into a comma-separated row to paste directly into Excel, Google Sheets, or a CSV file. Saves copying each item individually.

🗄️ SQL IN Clause Generation

Turn a list of IDs or names into a comma-separated string for SQL WHERE id IN (1, 2, 3) queries. Paste IDs one per line and get the CSV string in one click.

💰 Financial Number Formatting

Format raw numbers from exports or APIs with thousand-separator commas for reports, dashboards, invoices, or presentations. Handles millions and billions correctly.

🔀 Delimiter Conversion

Convert semicolon-separated or pipe-separated data to comma-separated format, or vice versa, when importing between different systems with different delimiter expectations.

🧹 CSV Data Cleaning

Remove extra commas, trim whitespace from each item, deduplicate entries, and sort alphabetically before reimporting cleaned data back into a database or spreadsheet.

🖥️ API & Config Work

Convert a list of environment variable values, allowed origins, or feature flag names into a comma-separated string for use in config files or API parameters.

📧 Email List Management

Convert a line-by-line list of email addresses into a comma-separated string to paste into the "To" or "CC" field of an email client that accepts comma-separated recipients.

📝 Content & Copywriting

Format numbered lists, bullet points, or inventory items from a content brief into comma-separated inline lists for body copy, meta descriptions, or structured content fields.

Thousand Separator Conventions by Country

Different countries and regions use different characters as thousand separators and decimal separators. Understanding these conventions is important when formatting numbers for international audiences or when processing data from different locales.

Region / Countries	Thousands Separator	Decimal Separator	One Million Example
🇺🇸🇬🇧🇦🇺🇨🇦🇨🇳🇯🇵 USA, UK, Australia, Canada, China, Japan	Comma `,`	Period `.`	`1,000,000.00`
🇩🇪🇫🇷🇮🇹🇪🇸🇧🇷🇵🇹 Germany, France, Italy, Spain, Brazil, Portugal	Period `.`	Comma `,`	`1.000.000,00`
🇨🇭🇸🇪🇳🇴🇩🇰🇫🇮 Switzerland, Sweden, Norway, Denmark, Finland	Space	Comma `,`	`1 000 000,00`
🇮🇳 India	Comma `,` (South Asian grouping)	Period `.`	`10,00,000.00`
🌐 International (ISO 80000)	Thin space	Period `.` or Comma `,`	`1 000 000.00`

This tool formats numbers using the US/UK convention (comma as thousands separator, period as decimal separator). If you need to convert to a different locale format, use the Find & Replace tab to swap commas and periods as needed after converting.

Indian Number Formatting (Lakh and Crore System)

India uses a unique grouping system. The first group from the right contains three digits, and all subsequent groups contain two digits. This system defines units of lakh (1,00,000 = 100,000) and crore (1,00,00,000 = 10,000,000). For example, 10 million is written as 1,00,00,000 (one crore) in the Indian system. This tool uses the international three-digit grouping standard.

CSV Format Guide — Comma-Separated Values Explained

CSV (Comma-Separated Values) is a plain-text file format used to store tabular data. Each line in a CSV file represents one row, and each field within that row is separated by a comma. CSV files are supported by virtually every spreadsheet application, database system, and programming language.

CSV File Structure Rules

Each record (row) occupies a single line, terminated by a line break.
Fields within a record are separated by commas.
Fields that contain commas, double-quotes, or line breaks must be enclosed in double-quote characters.
A double-quote appearing inside a quoted field is escaped by preceding it with another double-quote: "" .
The first line may optionally contain column headers (field names).
Spaces before and after commas are technically part of the field value, though many tools trim them automatically.

CSV vs TSV vs PSV

Format	Full Name	Delimiter	File Extension	Common Use
CSV	Comma-Separated Values	Comma `,`	`.csv`	Excel, Google Sheets, databases, APIs
TSV	Tab-Separated Values	Tab `\t`	`.tsv` or `.txt`	Bioinformatics, log exports, clipboard data
PSV	Pipe-Separated Values	Pipe `\|`	`.psv` or `.txt`	EDI data, legacy systems, Unix tools
SSV	Semicolon-Separated Values	Semicolon `;`	`.csv`	European CSV exports (where comma is decimal)

Use the Custom separator mode to convert between any of these formats — split by one delimiter and rejoin with another.

Why Use Semicolons Instead of Commas in CSV?

In countries where the comma is used as the decimal separator (Germany, France, Spain, Italy, and others), CSV files commonly use semicolons as the field delimiter instead of commas to avoid ambiguity. For example, a price value like 1.234,56 (one thousand two hundred thirty-four and 56 hundredths in German notation) would be misinterpreted if commas were used as field delimiters. Microsoft Excel in European locales automatically uses semicolons as the default CSV delimiter for this reason.

How to Use This Comma Separator Tool — Step-by-Step

Enter your text or numbers — Type directly in the Input box, click Paste to paste from clipboard, click Sample to load example data, or click Upload TXT to load a .txt or .csv file.
Select a conversion mode — Click the mode pill that matches your task: Add commas to numbers, Remove commas, Lines → CSV, CSV → Lines, Spaces → commas, or Custom separator. With Live mode on, output updates instantly.
Configure custom options (if needed) — For Custom separator mode, enter the character to split by and the character to join with. Check the RegEx box to use regular expression patterns.
Use Quick Actions — In the sidebar, use Trim each line, Remove blank lines, Remove duplicate lines, or Sort lines before or after converting to clean your data further.
Review in Preview mode — Switch to the Preview as list tab to see each comma-separated item as a numbered list, making it easy to verify the item count and content.
Copy or download — Click Copy Output to copy the result to clipboard, or Download TXT to save it. Use Use as Input to chain further transformations on the result.

Frequently Asked Questions — Comma Separator Tool

Answers to the most common questions about commas, CSV formatting, and number formatting.

How do I add commas to a number like 1000000?

Paste the number

into the Input box, select the Add commas to numbers mode, and the tool instantly outputs


        1,000,000

. You can process multiple numbers at once — paste one number per line and all will be formatted simultaneously. The tool correctly handles decimals (


        1234567.89

→


        1,234,567.89

) and negative numbers (


        -9876543

→


        -9,876,543

How do I convert a list to comma-separated values?

Paste your list with one item per line into the Input box and select Lines → comma-separated mode. For example, a list of apple, banana, and cherry (each on its own line) becomes


        apple, banana, cherry

. This is useful for generating SQL

IN

clauses, creating CSV rows, building API parameter strings, or formatting email recipient lists.

What is the difference between CSV and TSV?

CSV (Comma-Separated Values) uses commas as field delimiters while TSV (Tab-Separated Values) uses tab characters. TSV has an advantage when data fields themselves contain commas — tabs rarely appear inside text values, so less quoting is needed. CSV is more universally supported and is the default format for most spreadsheet applications. To convert a TSV file to CSV, use the Custom separator mode: set Split by to

\t

with RegEx enabled, and set Join with to

Why do European CSV files use semicolons instead of commas?

In countries that use a comma as the decimal separator (Germany, France, Spain, Italy, Netherlands, and others), using a comma as the CSV field delimiter would create ambiguity. For example, a number like


        1.234,56

in German notation contains a comma that would be misread as a field separator. To avoid this, Microsoft Excel and many European applications automatically use a semicolon (

) as the CSV delimiter when the system locale uses a comma as the decimal separator. Use the Custom separator mode to convert semicolon-separated European CSV files to standard comma-separated format.

How do I generate a SQL IN clause from a list?

Paste your IDs or values one per line, select Lines → comma-separated mode, then copy the output. For a numeric IN clause like


        WHERE id IN (1, 2, 3)

, paste the result directly. For string values, you'll need to wrap each item in quotes first — use the Find & Replace tab to add quotes around items, or use the Case Converter tool's "Wrap in quotes" extra transform to quote each line before converting to CSV.

Can I use regular expressions (RegEx) as a delimiter?

Yes. In the Custom separator mode, check the Use RegEx for split checkbox and enter a regular expression in the Split by field. For example:

\s+

splits on any whitespace;


        [,;|]

splits on commas, semicolons, or pipes simultaneously;

\t

splits on tabs. This makes it possible to handle messy or inconsistently delimited data in one pass.

Is my data processed securely?

Yes. All processing happens entirely in your browser using JavaScript. No data you enter is ever sent to any server, stored, or logged. The tool functions as a client-side application — it works completely offline once the page has loaded. This makes it safe to use with sensitive financial data, customer lists, confidential IDs, or any private information.

Explore more free online tools from IndexCraft to complement your data workflow.

🔡 Case Converter

Convert text to camelCase, snake_case, kebab-case, and 17 more formats.

📝 Word Counter

Count words, characters, sentences, and reading time.

🧹 Remove Empty Lines

Clean up blank and duplicate lines from text instantly.

⚙️ JSON Formatter

Format, validate, and minify JSON data online.

🔗 URL Encode / Decode

Encode or decode URL strings for web use.

✂️ Remove Whitespace