What is a .csv file?

You exported data from a database, downloaded a report, or received a spreadsheet from someone who wanted to keep things simple. It arrived as a CSV — a file so basic it's just text with commas. No formatting, no formulas, no data types, no merged cells. Just rows and values.

That simplicity is exactly why CSV has outlasted every proprietary format that tried to replace it. Every database exports CSV. Every spreadsheet imports it. Every programming language parses it in about three lines of code. The catch is that there's no real standard — different tools handle quoting, encoding, and delimiters differently, which is why importing a CSV sometimes turns your dates into numbers and your names into mojibake. Excel is particularly enthusiastic about "helpfully" reformatting data it didn't ask about.

For viewing, any text editor works. Excel, Google Sheets, and LibreOffice Calc give you a proper grid view. If you need to convert CSV to JSON or Excel format, fwip handles it in the browser. When you need to share raw data and don't want to assume what software the recipient has, CSV is the polite choice.