Basic HTTP cookie parser and serializer for HTTP servers.

$ npm install cookie

const cookie = require("cookie");
// import * as cookie from 'cookie';

Parse an HTTP Cookie header string and return an object of all cookie name-value pairs. The str argument is the string representing a Cookie header value and options is an optional object containing additional parsing options.

const cookieObject = cookie.parseCookie("foo=bar; equation=E%3Dmc%5E2");
// { foo: 'bar', equation: 'E=mc^2' }

• decode Specifies the function to decode a cookie-value. Defaults to decodeURIComponent.

Stringifies a cookie object into an HTTP Cookie header.

const cookieHeader = cookie.stringify({ a: "foo", b: "bar" });
// a=foo; b=bar

• encode Specifies the function to encode a cookie-value. Defaults to encodeURIComponent.

Parse an HTTP Set-Cookie header string and return an object of the options.

const setCookieObject = cookie.parseSetCookie("foo=bar; httpOnly");
// { name: "foo", value: "bar", httpOnly: true }

Note: Cookie follows the specification and ignores invalid attributes, but does not attempt to normalize or modify any attributes as a browser might. For example:

cookie.parseSetCookie(
  "session=abc; max-age=1.5; expires=invalid; custom=value; domain=example.com",
);
// { name: "session", value: "abc", domain: "example.com" }

• decode Specifies the function to decode a cookie-value. Defaults to decodeURIComponent.

Stringifies a Set-Cookie object into a Set-Cookie header string.

const setCookieHeader = cookie.stringifySetCookie({
  name: "foo",
  value: "bar",
});
// foo=bar

• encode Specifies the function to encode a cookie-value. Defaults to encodeURIComponent.

The cookie object represents all cookie name-value pairs in a Cookie header, where { name: "value" } is used for name=value.

The Set-Cookie object represents all the options in a Set-Cookie header.

The name of the cookie.

The value of a cookie after it has been decoded.

Specifies the number (in seconds) to be the value for the Max-Age Set-Cookie attribute.

The cookie storage model specification states that if both expires and maxAge are set, then maxAge takes precedence, but it is possible not all clients by obey this, so if both are set, they should point to the same date and time.

Specifies the Date object to be the value for the Expires Set-Cookie attribute. When no expiration is set, clients consider this a "non-persistent cookie" and delete it when the current session is over.

The cookie storage model specification states that if both expires and maxAge are set, then maxAge takes precedence, but it is possible not all clients by obey this, so if both are set, they should point to the same date and time.

Specifies the value for the Domain Set-Cookie attribute. When no domain is set, clients consider the cookie to apply to the current domain only.

Specifies the value for the Path Set-Cookie attribute. When no path is set, the path is considered the "default path".

Enables the HttpOnly Set-Cookie attribute. When enabled, clients will not allow client-side JavaScript to see the cookie in document.cookie.

Enables the Secure Set-Cookie attribute. When enabled, clients will only send the cookie back if the browser has an HTTPS connection.

Enables the Partitioned Set-Cookie attribute. When enabled, clients will only send the cookie back when the current domain and top-level domain matches.

This is an attribute that has not yet been fully standardized, and may change in the future. This also means clients may ignore this attribute until they understand it. More information about can be found in the proposal.

Specifies the value for the Priority Set-Cookie attribute.

• 'low' will set the Priority attribute to Low.
• 'medium' will set the Priority attribute to Medium, the default priority when not set.
• 'high' will set the Priority attribute to High.

More information about priority levels can be found in the specification.

Specifies the value for the SameSite Set-Cookie attribute.

• true will set the SameSite attribute to Strict for strict same site enforcement.
• 'lax' will set the SameSite attribute to Lax for lax same site enforcement.
• 'none' will set the SameSite attribute to None for an explicit cross-site cookie.
• 'strict' will set the SameSite attribute to Strict for strict same site enforcement.

More information about enforcement levels can be found in the specification.

Cookie accepts encode or decode options for processing a cookie-value. Since the value of a cookie has a limited character set (and must be a simple string), these functions are used to transform values into strings suitable for a cookies value.

The default encode function is the global encodeURIComponent.

The default decode function is the global decodeURIComponent, wrapped in a try..catch. If an error is thrown it will return the cookie's original value. If you provide your own encode/decode scheme you must ensure errors are appropriately handled.

The following example uses this module in conjunction with the Node.js core HTTP server to prompt a user for their name and display it back on future visits.

var cookie = require("cookie");
var escapeHtml = require("escape-html");
var http = require("http");
var url = require("url");

function onRequest(req, res) {
  // Parse the query string
  var query = url.parse(req.url, true, true).query;

  if (query && query.name) {
    // Set a new cookie with the name
    res.setHeader(
      "Set-Cookie",
      cookie.stringifySetCookie({
        name: "name",
        value: String(query.name),
        httpOnly: true,
        maxAge: 60 * 60 * 24 * 7, // 1 week
      }),
    );

    // Redirect back after setting cookie
    res.statusCode = 302;
    res.setHeader("Location", req.headers.referer || "/");
    res.end();
    return;
  }

  // Parse the cookies on the request
  var cookies = cookie.parseCookie(req.headers.cookie || "");

  // Get the visitor name set in the cookie
  var name = cookies.name;

  res.setHeader("Content-Type", "text/html; charset=UTF-8");

  if (name) {
    res.write("<p>Welcome back, <b>" + escapeHtml(name) + "</b>!</p>");
  } else {
    res.write("<p>Hello, new visitor!</p>");
  }

  res.write('<form method="GET">');
  res.write(
    '<input placeholder="enter your name" name="name"> <input type="submit" value="Set Name">',
  );
  res.end("</form>");
}

http.createServer(onRequest).listen(3000);

npm test

npm run bench

     name                   hz     min     max    mean     p75     p99    p995    p999     rme  samples
   · simple       8,566,313.09  0.0000  0.3694  0.0001  0.0001  0.0002  0.0002  0.0003  ±0.64%  4283157   fastest
   · decode       3,834,348.85  0.0001  0.2465  0.0003  0.0003  0.0003  0.0004  0.0006  ±0.38%  1917175
   · unquote      8,315,355.96  0.0000  0.3824  0.0001  0.0001  0.0002  0.0002  0.0003  ±0.72%  4157880
   · duplicates   1,944,765.97  0.0004  0.2959  0.0005  0.0005  0.0006  0.0006  0.0008  ±0.24%   972384
   · 10 cookies     675,345.67  0.0012  0.4328  0.0015  0.0015  0.0019  0.0020  0.0058  ±0.75%   337673
   · 100 cookies     61,040.71  0.0152  0.4092  0.0164  0.0160  0.0196  0.0228  0.2260  ±0.71%    30521   slowest
   ✓ parse top-sites (15) 22945ms
     name                                  hz     min     max    mean     p75     p99    p995    p999     rme   samples
   · parse accounts.google.com   7,164,349.17  0.0000  0.0929  0.0001  0.0002  0.0002  0.0002  0.0003  ±0.09%   3582184
   · parse apple.com             7,817,686.84  0.0000  0.6048  0.0001  0.0001  0.0002  0.0002  0.0003  ±1.05%   3908844
   · parse cloudflare.com        7,189,841.70  0.0000  0.0390  0.0001  0.0002  0.0002  0.0002  0.0003  ±0.06%   3594921
   · parse docs.google.com       7,051,765.61  0.0000  0.0296  0.0001  0.0002  0.0002  0.0002  0.0003  ±0.06%   3525883
   · parse drive.google.com      7,349,104.77  0.0000  0.0368  0.0001  0.0001  0.0002  0.0002  0.0003  ±0.05%   3674553
   · parse en.wikipedia.org      1,929,909.49  0.0004  0.3598  0.0005  0.0005  0.0007  0.0007  0.0012  ±0.16%    964955
   · parse linkedin.com          2,225,658.01  0.0003  0.0595  0.0004  0.0005  0.0005  0.0005  0.0006  ±0.06%   1112830
   · parse maps.google.com       4,423,511.68  0.0001  0.0942  0.0002  0.0003  0.0003  0.0003  0.0005  ±0.08%   2211756
   · parse microsoft.com         3,387,601.88  0.0002  0.0725  0.0003  0.0003  0.0004  0.0004  0.0005  ±0.09%   1693801
   · parse play.google.com       7,375,980.86  0.0000  0.1994  0.0001  0.0001  0.0002  0.0002  0.0003  ±0.12%   3687991
   · parse support.google.com    4,912,267.94  0.0001  2.8958  0.0002  0.0002  0.0003  0.0003  0.0005  ±1.28%   2456134
   · parse www.google.com        3,443,035.87  0.0002  0.2783  0.0003  0.0003  0.0004  0.0004  0.0007  ±0.51%   1721518
   · parse youtu.be              1,910,492.87  0.0004  0.3490  0.0005  0.0005  0.0007  0.0007  0.0011  ±0.46%    955247
   · parse youtube.com           1,895,082.62  0.0004  0.7454  0.0005  0.0005  0.0006  0.0007  0.0013  ±0.64%    947542   slowest
   · parse example.com          21,582,835.27  0.0000  0.1095  0.0000  0.0000  0.0001  0.0001  0.0001  ±0.13%  10791418

• RFC 6265: HTTP State Management Mechanism
• Same-site Cookies

MIT