Data Formats

What Is a CSV File? Format, Structure, Examples, and Common Pitfalls

CSV is a family of plain-text tabular formats where records are rows and fields are separated by a delimiter, commonly a comma.

Published Aug 20, 2026

CSV in one sentence

CSV means comma-separated values, but real systems use dialects with different delimiters, quoting rules, encodings and line endings.

Rows, columns and fields

name,note,active
Ada,"Hello, world",true
Lin,"Line 1
Line 2",false

Headers: common, useful, not magical

The first row often names columns, but the format itself does not universally guarantee that it is a header. Import settings and data contracts decide.

Delimiters and CSV dialects

Choice	Where it appears
Comma	Common CSV interchange
Semicolon	Locales where comma is a decimal separator
Tab	TSV and spreadsheet copy/paste

Quotes, commas, newlines and escaped quotes

A quoted field may contain delimiters and line breaks. A literal quote inside a quoted field is commonly represented by two quotes.

id,note
1,"She said ""ready"""

What CSV does not preserve well

Nested objects and arrays
Strong numeric, boolean and null types
Multiple sheets, formulas and formatting
One universal encoding or dialect

Common pitfalls

Inconsistent field counts
Unescaped delimiters or newlines
Encoding mismatch
Spreadsheet auto-conversion of identifiers and dates

Try the example

See quoting in a real CSV preview

A comma and a line break require CSV quoting in the generated table.

[{name: Ada, note: Hello, world}, {name: Lin, note: Line 1\nLine 2}]

Expected result: The preview contains two rows and quotes fields containing comma or newline characters.

Try a real conversion

Create CSV from structured data

Preview columns, quoting and line breaks using the local JSON to CSV workflow.

Open JSON to CSV Converter →