What is .csv?

.csv stands for Comma-Separated Values, a plain-text format for storing tabular data like spreadsheets, reports, or exports. Each line represents a row, and values in the row are separated by commas or other delimiters.

This quick guide explains when to use .csv files, how to open them on any device, and how to share them instantly with FileXhost.

When to use .csv files

You are exporting data from apps such as analytics tools, CRMs, or databases.
You want a lightweight, tool-agnostic format that opens in Excel, Sheets, and text editors.
You need to import or migrate data between systems without proprietary file formats.

How to open .csv files

.csv files open in spreadsheet tools like Microsoft Excel, Google Sheets, Apple Numbers, and most database or analytics tools. You can also upload a .csv file to FileXhost to preview, explore, and share it through an instant public link.

Algorithm details

CSV files follow a simple text-based structure defined by RFC 4180. Each record is located on a separate line, delimited by a line break (CRLF). Fields within a record are separated by commas. If a field contains a comma, newline, or double quote, it must be enclosed in double quotes. Double quotes inside a quoted field are escaped by another double quote.

Browser & platform support

Desktop: Browsers typically download CSVs or display them as raw text. Extensions or apps like FileXhost are needed for a grid view.
Mobile: Requires a spreadsheet viewer app (Excel, Sheets) or a file viewer utility.
OS: Universally supported by all operating systems as plain text.

Format comparison

Feature	Details
Structure	Flat, 2D tabular data. Cannot handle nested data structures like JSON or XML.
Formatting	None. Stores only raw data values. No fonts, colors, borders, or formulas.
Size	Generally smaller than XLSX for simple data, but larger than binary formats for large datasets due to text redundancy.
Compatibility	The most compatible data format in existence. Readable by almost any data tool.

How to create csv files

Spreadsheet Software: Excel, Google Sheets, Numbers (File > Export > CSV).
Text Editors: Notepad, VS Code (manually typing values separated by commas).
Programming: Python (pandas, csv module), JavaScript (fs, json2csv), SQL (EXPORT TO CSV).
Databases: Most SQL databases allow exporting query results directly to CSV.

How to convert csv files

FileXhost: Upload CSV files to view them as interactive tables in the browser.
Excel/Sheets: Open CSV and 'Save As' XLSX or PDF.
Online Converters: Convertio, CloudConvert (CSV to JSON, XML, PDF).
CLI: csvkit (csvjson, in2csv), Miller, Pandas.

Advantages & disadvantages

Advantages

Human-readable and editable in any text editor
Universally supported by virtually all data applications
Simple structure makes it easy to generate programmatically
No proprietary lock-in

Disadvantages

No support for styling, formulas, or multiple sheets
No standard way to specify data types (everything is text)
Issues with delimiter collision (commas in data) if not escaped properly
Encoding issues (UTF-8 vs BOM) can cause display errors

Tools & software

Spreadsheets

Microsoft Excel, Google Sheets, Apple Numbers, LibreOffice Calc

Text Editors

VS Code (with CSV extensions), Notepad++, Sublime Text

Data Tools

Tableau, PowerBI, DBeaver, Pandas (Python), RStudio

Command Line

csvkit, xsv, Miller (mlr), awk, sed

Frequently asked questions

Why does Excel mess up my CSV dates or long numbers?

Excel tries to auto-detect formats. It may convert '00123' to '123' or long IDs to scientific notation. Use 'Data > Get Data > From Text/CSV' to specify column types manually.

What is the difference between CSV and Excel (XLSX)?

CSV is plain text with raw data only. XLSX is a zipped XML binary format that supports formulas, formatting, charts, multiple sheets, and macros.

How do I handle commas inside my data?

Standard CSV readers handle this by enclosing the field in double quotes. For example: "City, Country".

Why do I see weird characters in my CSV?

This is usually an encoding mismatch. Ensure your file is saved as UTF-8. Some Excel versions require a UTF-8 BOM to display characters correctly.

Can a CSV have multiple sheets?

No, CSV supports only a single table of data. If you need multiple sheets, you must use XLSX or multiple CSV files.

Technical specs

File type: Spreadsheet
Extension: .csv
MIME type: text/csv, application/csv, text/comma-separated-values
Compression: Uncompressed
Max file size on FileXhost: Up to 25 MB per file on the free plan and up to 1 GB on Pro FileXhost accounts.

Upload your .csv file to FileXhost to get a clean, shareable URL in seconds. View the file in a modern browser, protect access with optional settings, and let others download it without any confusing ads or cluttered file pages.

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