What does CSV stand for? CSV stands for comma-separated values, a simple file format that stores a table as plain text. Each line is one row, and commas mark where one column ends and the next begins. A file named contacts.csv might hold names, emails and phone numbers that any spreadsheet program can open.
The format is popular because almost every tool can read it. Banks offer CSV downloads of transactions, online stores export orders as CSV, and databases use it to move data in and out. It has no formulas, colors or charts, just the values.
Quick facts
Stands for
Comma-separated valuesType
Initialism, said C S VFile extension
.csvUsed in
Spreadsheets, bank exports, databases, mailing listsRelated formats
TSV (tab-separated values), JSONHolds
Text and numbers only, no formatting
What does CSV stand for, and what is inside the file?
The name describes the file exactly: values, separated by commas. Here is a small CSV file opened in a plain text editor:
name,city,points
Ana,Denver,42
Ben,Tulsa,37
Cara,Boise,51
The first line is usually a header row that names each column. Every line after it is one record. Open the same file in a spreadsheet program and you see a neat grid with three columns and three rows of data. Nothing else is stored: no bold text, no cell colors, no formulas.
Rules for commas, quotes and line breaks
Real data often contains commas, which could confuse the file. CSV handles that with double quotes.
- Commas inside a value: wrap the value in quotes, as in "Austin, TX".
- Quotes inside a value: double them, so She said "hi" becomes "She said ""hi""".
- Line breaks inside a value: also wrap the value in quotes.
- Same number of fields: each row should have as many values as the header.
Not every program follows the same rules, which is why a CSV from one system sometimes looks jumbled in another.
Where you will run into CSV files
| Setting | What the CSV holds |
|---|---|
| Online banking | A list of transactions to download |
| Online store or shop admin | Orders, products or customer lists |
| School or office | Grade lists, sign up sheets, survey results |
| Email marketing | Contact lists to import |
| Programming | Data moved between apps or a SQL database |
A button labeled "Export to CSV" means the site will save its table as one of these files.
Common problems and quick fixes
- Leading zeros vanish. A ZIP code like 02134 may turn into 2134 when a spreadsheet opens the file. Import the column as text instead of opening the file directly.
- Everything lands in one column. Some regions use semicolons instead of commas. Choose the right separator in the import screen.
- Strange characters appear. Accented letters can break if the file encoding does not match. Save as UTF-8 when you can.
- Formatting disappears. CSV cannot store it. Save a regular spreadsheet file if you need colors and formulas.
CSV vs other data formats
- CSV vs spreadsheet file: a spreadsheet file keeps formulas, sheets and styles; a CSV keeps only one table of values.
- CSV vs TSV: TSV uses tabs instead of commas, which helps when the data is full of commas.
- CSV vs JSON: JSON can hold nested data, like a customer with a list of orders. CSV is flat, one row per record.
- CSV vs PDF: a PDF is for reading and printing; a CSV is for working with the data.
How to say and write CSV
Say the three letters: "see ess vee." CSV takes all caps and no dots, and it pairs with a, not an: "a CSV file." The plural is CSVs. On its own it works as a noun too: "Send me the CSV." For more file and data terms, browse our tech acronyms list.
Examples: "Export the report as a CSV and attach it." "The CSV has 2,000 rows." "Check the CSV for missing commas before you import it."
Questions people ask
How do I open a CSV file?
Double click it to open it in a spreadsheet program, or open it in any text editor to see the raw lines. To keep leading zeros, use the program's import option and set those columns as text.
Is a CSV file the same as a spreadsheet?
Not quite. A CSV holds only plain values in one table. A spreadsheet file can also store formulas, several sheets, charts and formatting.
Why does my CSV show everything in one column?
The program probably expected a different separator, such as a semicolon. Use the import screen and pick comma as the delimiter.
Can a CSV file contain commas in the data?
Yes. Any value that includes a comma should be wrapped in double quotes so programs know it is one value.
Is CSV safe to share?
The format itself is plain text. Still, check the contents before you send it, since exports often include names, emails or account details.