`res.attachment()`

Sets the Content-Disposition header to attachment to prompt a download.

Since Express 4 Spec ↗

Syntax

res.attachment([filename])

Parameters

Name	Type	Required	Description
`filename`	`string`	No	Suggested download filename; also sets Content-Type from its extension.

Returns

Response — The response object, for chaining.

Examples

app.get('/report', (req, res) => {
  res.attachment('report.csv');
  res.send('id,name\n1,Ada\n');
});

Output

Content-Disposition: attachment; filename="report.csv"
Content-Type: text/csv; charset=utf-8

app.get('/blob', (req, res) => {
  res.attachment();
  res.send(buffer);
});

Output

Content-Disposition: attachment

Notes

Only sets headers; you still send the body yourself. For sending an existing file from disk as a download use `res.download()`, which also handles streaming and 404s.