Documents

What is a CSV file?

Updated Jul 2026

Definition

CSV (Comma-Separated Values) is a plain text format for storing data in rows and columns, with a comma separating each value. It's the simplest way to move a table between programs because almost any spreadsheet, database, or script can read it. The catch is that it holds only raw data, no formulas, formatting, or multiple sheets.

CSVComma-Separated Values

Extension: .csv
Type: Documents
Typically: Data, spreadsheets

Why CSV exists

CSV goes back to the early days of business computing, when programs needed a plain text way to trade tables of data without agreeing on a shared file format. A comma between values and a line break between rows was enough, and it stuck because almost any language or tool can read plain text.

Under the hood a CSV file is just text you could open in any editor. Each line is a row, each comma marks a new column, and the first line is often a header naming each column. There's no styling, no cell colors, no formulas, just the values themselves, which is exactly what makes it easy for one program to hand data to another.

That plainness is why people run into CSV constantly. Exporting contacts, bank transactions, survey results, or a spreadsheet from one tool almost always offers CSV as an option, and importing data into another tool usually asks for it too. The trouble starts when a spreadsheet app saves extra formatting or a different delimiter, and the file that comes out doesn't line up the way it should in the next program.

The trade-offs

Strengths

Opens in almost any spreadsheet, database, or programming language
Small file size since it's just plain text
Easy to read, edit, or generate by hand if needed
Works the same across Mac, Windows, and other systems

Watch-outs

No formulas, formatting, colors, or multiple sheets
Can misread commas inside a value if the file isn't built carefully
No fixed standard for things like text encoding or line endings
Loses any structure beyond a single flat table

A note on privacy

A CSV file doesn't carry hidden metadata the way a photo does, but the rows inside it often are the sensitive part, bank transactions, customer contacts, survey answers, or medical records. Uploading that file to an online converter means a table full of real personal data passes through someone else's server. Converting it on your own computer keeps every row where it started.

Convert a CSV file

Questions

How do I open a CSV file?

Most spreadsheet apps on Mac and Windows open a CSV directly, showing it as rows and columns like any other spreadsheet. You can also open it in a plain text editor if you just want to see the raw values.

Is CSV better than an Excel file?

For plain data exchange, yes: CSV opens almost anywhere and stays small. For anything with formulas, formatting, or multiple sheets, no: those need a spreadsheet format built to hold that extra structure.

Why do exports from apps come as CSV?

CSV is the simplest table format nearly every program can read and write, so it's the safest choice when an app doesn't know what you'll open the data with next.

Can I convert a CSV file without uploading it?

Yes. A desktop app like Morphjet converts CSV files on your own computer, so a spreadsheet full of personal or financial data never leaves your machine.

Why does my CSV look wrong when I open it?

This usually happens when a value itself contains a comma, or the file uses a different text encoding than the program expects. Both are common enough that most spreadsheet apps offer an import step to fix the column mapping.

Morphjet opens and converts CSV and 1,800+ other formats, all on your own computer. Launching this July.