What is a CSV file?
A CSV file is a plain-text table in which each line is a row and the values in a row are separated by commas. Almost every spreadsheet, database and business system can read and write it.
A CSV example
A file of three contacts looks like this, with a header row first:
- name,email,plan
- Ada Lovelace,[email protected],Growth
- "Turing, Alan",[email protected],Starter
Values that contain a comma, like the last name, are wrapped in double quotes.
The CSV delimiter and encoding
The CSV delimiter is usually a comma, but files from countries that use a comma as the decimal mark often use semicolons instead. Save files as UTF-8 so accented names survive; some spreadsheet apps also need a byte order mark to read UTF-8 correctly.
Common CSV problems
- CSV leading zeros: spreadsheet apps can turn a code like 00123 into 123.
- Long numbers such as account numbers shown in scientific notation.
- Dates read in the wrong order, such as 03/04 as March or April.
- Line breaks inside a value that split one row into two.
How to open a CSV file
Any text editor shows the raw file, and spreadsheet apps open it as a table. Arkenso Docs opens .csv files as live spreadsheets your team can edit together, and exports them to Excel at any time.
Last reviewed 2026-11-01.