FileHint

text/csv

The MIME type for CSV data, standardised in RFC 4180. The lingua franca for tabular data in HTTP responses and email attachments.

Typical extensions

Primary uses

  • Downloads from web forms (sales reports, member lists)
  • Input and output in data-analysis pipelines
  • Pasting into Excel or a BI tool

In a browser

Most browsers download CSV. Specifying `charset=utf-8` in the Content-Type parameter helps Excel avoid mojibake on some locales.

On a server

For very large exports, stream with `Transfer-Encoding: chunked` so clients see the first rows faster.

In email

Common as an attachment, but watch for CSV Injection — user-generated cells beginning with `=` or `+` can execute when opened in Excel.

References