`res.set()`

Sets one or more response header fields.

Since Express 4 Spec ↗

Syntax

res.set(field[, value])  /  res.set(object)

Parameters

Name	Type	Required	Description
`field`	`string \| object`	Yes	A header name, or an object of name/value pairs.
`value`	`string \| string[]`	No	The header value when `field` is a string.

Returns

Response — The response object, for chaining.

Examples

app.get('/x', (req, res) => {
  res.set('Cache-Control', 'no-store');
  res.send('ok');
});

Output

Cache-Control: no-store

app.get('/y', (req, res) => {
  res.set({
    'X-Request-Id': req.id,
    'X-Frame-Options': 'DENY',
  });
  res.json({ ok: true });
});

Notes

Alias `res.header()`. Headers must be set before the body is sent or Express throws `ERR_HTTP_HEADERS_SENT`. `res.get('Field')` reads a header you have set. Setting `Content-Type` is better done via `res.type()`.