.CSV file extension

To open .CSV files on Windows, right-click the .CSV file and select 'Open with'.

.CSV files can be opened using spreadsheet applications like Microsoft Excel or Google Sheets. To open a .CSV file, use a compatible app rather than renaming the file extension.

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Last updated: June 11, 2026 · Reviewed by Julian Stricker

What “reviewed” means on this page

Format fit: whether the “what is this file?” description matches common real-world use of the extension, including category, typical MIME types, and aliases.
Opening paths: whether Windows / macOS / Linux steps read plausibly for current OS dialogs and default apps; we remove fantasy menus and unsafe shortcuts.
Security framing: whether risk notes match the extension class (for example executables vs plain data) and whether affiliate wording does not contradict the security section.
Sources and further reading: whether external links point to vendors, standards bodies, or other primary references where possible; we avoid inventing details we cannot ground.
Limits: this is clarity and safety-messaging QA, not a guarantee that every statement is exhaustive or that every binary you download is harmless.

Full methodology in the Imprint — The Imprint also states where AI is used and what that does—and does not—replace.

Open on your device

Choose your operating system for a dedicated step-by-step opening guide.

How to open .CSV files

Use these platform-specific instructions to open .CSV files safely.

Windows

Right-click the .CSV file and select 'Open with'.
Choose Microsoft Excel or another spreadsheet application.

Full Windows guide

Mac

Control-click the .CSV file and select 'Open With'.
Choose Numbers or a compatible spreadsheet app.

Full Mac guide

Linux

Right-click the .CSV file and select 'Open With'.
Choose LibreOffice Calc or another spreadsheet program.

Full Linux guide

iOS

Open the .CSV file in the Files app and tap 'Share'.
Select an app like Numbers to view the file.

Full iOS guide

Android

Open the .CSV file from the Files or Downloads app.
Select a spreadsheet app like Google Sheets to open the file.

Full Android guide

Security notes

Open .CSV files only from trusted sources to avoid malicious data.
Be cautious of .CSV files that prompt for macros or scripts.
Regularly update your spreadsheet software to patch security vulnerabilities.

If you did not expect this file

This extension is usually plain data, text, or structured content—not a program by itself. The practical risk is social engineering (a scam attachment or misleading filename). For trusted senders you rarely need heavy-handed antivirus wording; use these tools when you want an extra check on unexpected downloads.

Avast

Avast offers free and premium antivirus software that protects against viruses, malware, ransomware, and phishing. Scan files before opening them to ensure safety.

Norton

Norton 360 delivers comprehensive antivirus protection, VPN, and identity theft monitoring. Scan files for threats before opening to keep your device secure.

We may earn a commission when you use affiliate links. This supports our free file extension guides.

Can't open this file?

These are the most common causes and fixes when .CSV files fail to open.

Common reasons

File opens with incorrect formatting
Special characters not displaying correctly

Fix steps

Check the delimiter used in the .CSV file (commas, semicolons, etc.).
Configure the application to use the correct delimiter when opening the file.

OS-specific troubleshooting

Convert .CSV to other formats

Use conversion tools to change .CSV files into formats your software supports.

What is a .CSV file?

.CSV stands for Comma-Separated Values, a format that stores data in a tabular form with each line representing a data record. It is widely used for data exchange due to its simplicity and compatibility with many applications.

Background

.CSV files have been around since the early days of computing and are a staple for data interchange between different systems. They are particularly popular in business and data analysis contexts because they can be easily imported into spreadsheets and databases. Each line in a .CSV file corresponds to a row in a table, and fields within each line are separated by commas, making it easy to parse and manipulate data. Despite their simplicity, .CSV files can sometimes cause issues with data interpretation, especially if the data contains commas or line breaks. To mitigate this, some variations of the format allow for quotation marks to encapsulate fields. Due to its plain text nature, .CSV files are lightweight and can be opened and edited with basic text editors, though they are most commonly used with spreadsheet software.

Common MIME types: text/csv

Common .CSV issues

File opens with incorrect formatting

The .CSV file may not display correctly if the delimiter used in the file does not match the expected delimiter in the application.

Check the delimiter used in the .CSV file (commas, semicolons, etc.).
Configure the application to use the correct delimiter when opening the file.

Special characters not displaying correctly

Non-standard characters may not render properly if the file's encoding is not supported by the application.

Ensure the file is saved with UTF-8 encoding.
Open the file in a text editor and re-save it with the correct encoding if necessary.

FAQ

Can I convert a .CSV file to another format?

Yes, most spreadsheet applications allow you to save .CSV files in other formats like .XLSX or .ODS.

Why does my .CSV file show all data in one column?

This happens when the delimiter used in the file does not match the expected delimiter in the software. Adjust the delimiter settings in the application.

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