What Is a CSV File?
A CSV file (Comma-Separated Values) is a plain-text file where each line represents one row of a table and commas separate the columns. Because it's just text, every spreadsheet program, database, and programming language can read it without special drivers — that's why it's the universal format for moving data between systems.
What a CSV file looks like inside
Open any CSV in a text editor (not Excel) and you'll see something like this:
name,email,country
Ada Lovelace,ada@example.com,UK
Grace Hopper,grace@example.com,US
The first line is usually the header row — column names. Every line after it is one record. Commas are the default delimiter; newlines end each row.
When CSV beats Excel (.xlsx)
Use CSV when you need to import data into a database, send data to an API, share with a non-Excel user, version-control your data in Git, or move thousands of rows fast. Excel files are bigger, can't be diffed, and can carry macros that won't run elsewhere.
Stick with Excel when you need formulas, charts, multiple sheets, or formatting like bold and colors. CSV stores values only — no styles, no formulas, no tabs.
Common pitfalls
- Commas inside values must be wrapped in double quotes:
"Hopper, Grace",grace@example.com.
- Encoding matters. Always save as UTF-8 so accents and non-Latin characters survive the round-trip.
- Regional delimiters. Excel in many European locales uses
;instead of,— see our delimiters guide.
Frequently asked questions
Is a CSV the same as Excel?
No. CSV is plain text with no formatting, formulas, or sheets. Excel (.xlsx) is a binary spreadsheet format that can contain all of those.
Can a CSV have multiple sheets?
No. One CSV file = one table. If you need multiple sheets, use .xlsx or split the data into separate CSV files.
What program opens a CSV?
Excel, Google Sheets, Numbers, LibreOffice Calc, and any text editor all open CSVs natively.