What Is a .csv File? .csv Format, MIME & How to Open

Quick facts

Extension.csv

File typeCSV Data File

MIME typetext/csv

CategoryData & Text

Charset—

CompressibleYes

Format familycsv

What is .csv

What is a .csv file?

A .csv file is a CSV Data File — Comma-separated values for tabular data interchange.

In the mime-db registry it maps to text/csv, and it is marked as compressible. When serving .csv over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to text/csv and is used by CSV among others — and is delivered over HTTP via the Content-Type header.

How to open .csv files

Use Excel or VS Code to open and edit .csv files.
Any text editor (Notepad, VS Code) can inspect the raw content as text.

Developer info

When served over HTTP, responses should set the following header:

Content-Type: text/csv

Common software that reads/writes .csv:

ExcelVS CodePython

Relation chain

.csvextension of

format

csvserved as

mime type

text/csvsent via header

http header

Related extensions

Related MIME types

Related programming languages

CSV

.csv

Common uses

Tabular data export and import
Spreadsheet interchange
Machine-learning datasets

How to edit .csv files

Open the file with Excel, make your changes and save.
Most editors preserve the original formatting and encoding — avoid changing the charset.

How to create .csv files

Create a new file and save it with the .csv extension, or export this format from Excel.

Example

name,age,city
John,30,New York
Ada,36,London

Header row — column names
Data rows — comma-separated values

Frequently asked questions

What programs can open .csv files?

Common options include Excel, VS Code, Python. You can also open many of these files with built-in viewers or a browser.

How do I create a .csv file?

Create a new file in any text editor or the app that owns the format and save it with the .csv extension.

What is the relationship between .csv and the text/csv MIME type?

text/csv is the media type identifier used for .csv files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-09-13

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