/js-cookie

A simple, lightweight JavaScript API for handling browser cookies

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A simple, lightweight JavaScript API for handling cookies

If you're viewing this at https://github.com/js-cookie/js-cookie, you're reading the documentation for the master branch. View documentation for the latest release.

Installation

NPM

JavaScript Cookie supports npm under the name js-cookie.

$ npm install js-cookie --save

Direct download

The source comes as an ES module. If you download it here directly, you must include it as such.

Example:

<script type="module" src="./js.cookie.mjs"></script>
<script type="module">
  import Cookies from './js.cookie.mjs'

  Cookies.set('foo', 'bar')
</script>

Not all browsers support ES modules natively yet. For this reason the npm package/release comes with both an ES module as well as an UMD module variant. Include the module along with the fallback to account for this:

<script type="module" src="/path/to/js.cookie.mjs"></script>
<script nomodule src="/path/to/js.cookie.js"></script>

Note the different extensions: .mjs denotes an ES module.

CDN

Alternatively, include it via jsDelivr CDN:

<script src="https://cdn.jsdelivr.net/npm/js-cookie@2/src/js.cookie.min.js"></script>

Never include the source directly from GitHub (http://raw.github.com/...). The file is being served as text/plain and as such may be blocked because of the wrong MIME type. Bottom line: GitHub is not a CDN.

ES Module

Example for how to import the ES module from another module:

import Cookies from './node_modules/js-cookie/dist/js.cookie.mjs'

Cookies.set('foo', 'bar')

Basic Usage

Create a cookie, valid across the entire site:

Cookies.set('name', 'value')

Create a cookie that expires 7 days from now, valid across the entire site:

Cookies.set('name', 'value', { expires: 7 })

Create an expiring cookie, valid to the path of the current page:

Cookies.set('name', 'value', { expires: 7, path: '' })

Read cookie:

Cookies.get('name') // => 'value'
Cookies.get('nothing') // => undefined

Read all visible cookies:

Cookies.get() // => { name: 'value' }

Note: It is not possible to read a particular cookie by passing one of the cookie attributes (which may or may not have been used when writing the cookie in question):

Cookies.get('foo', { domain: 'sub.example.com' }) // `domain` won't have any effect...!

The cookie with the name foo will only be available on .get() if it's visible from where the code is called; the domain and/or path attribute will not have an effect when reading.

Delete cookie:

Cookies.remove('name')

Delete a cookie valid to the path of the current page:

Cookies.set('name', 'value', { path: '' })
Cookies.remove('name') // fail!
Cookies.remove('name', { path: '' }) // removed!

IMPORTANT! When deleting a cookie and you're not relying on the default attributes, you must pass the exact same path and domain attributes that were used to set the cookie:

Cookies.remove('name', { path: '', domain: '.yourdomain.com' })

Note: Removing a nonexistent cookie does not raise any exception nor return any value.

Namespace conflicts

If there is any danger of a conflict with the namespace Cookies, the noConflict method will allow you to define a new namespace and preserve the original one. This is especially useful when running the script on third party sites e.g. as part of a widget or SDK.

// Assign the js-cookie api to a different variable and restore the original "window.Cookies"
var Cookies2 = Cookies.noConflict()
Cookies2.set('name', 'value')

Note: The .noConflict method is not necessary when using AMD or CommonJS, thus it is not exposed in those environments.

JSON

js-cookie provides unobtrusive JSON storage for cookies.

When creating a cookie you can pass an Array or Object Literal instead of a string in the value. If you do so, js-cookie will store the string representation of the object according to JSON.stringify:

Cookies.set('name', { foo: 'bar' })

When reading a cookie with the default Cookies.get api, you receive the string representation stored in the cookie:

Cookies.get('name') // => '{"foo":"bar"}'
Cookies.get() // => { name: '{"foo":"bar"}' }

When reading a cookie with the Cookies.getJSON api, you receive the parsed representation of the string stored in the cookie according to JSON.parse:

Cookies.getJSON('name') // => { foo: 'bar' }
Cookies.getJSON() // => { name: { foo: 'bar' } }

Encoding

This project is RFC 6265 compliant. All special characters that are not allowed in the cookie-name or cookie-value are encoded with each one's UTF-8 Hex equivalent using percent-encoding.
The only character in cookie-name or cookie-value that is allowed and still encoded is the percent % character, it is escaped in order to interpret percent input as literal.
Please note that the default encoding/decoding strategy is meant to be interoperable only between cookies that are read/written by js-cookie. To override the default encoding/decoding strategy you need to use a converter.

Note: According to RFC 6265, your cookies may get deleted if they are too big or there are too many cookies in the same domain, more details here.

Cookie Attributes

Cookie attributes defaults can be set globally by setting properties of the Cookies.defaults object or individually for each call to Cookies.set(...) by passing a plain object in the last argument. Per-call attributes override the default attributes.

expires

Define when the cookie will be removed. Value can be a Number which will be interpreted as days from time of creation or a Date instance. If omitted, the cookie becomes a session cookie.

To create a cookie that expires in less than a day, you can check the FAQ on the Wiki.

Default: Cookie is removed when the user closes the browser.

Examples:

Cookies.set('name', 'value', { expires: 365 })
Cookies.get('name') // => 'value'
Cookies.remove('name')

path

A String indicating the path where the cookie is visible.

Default: /

Examples:

Cookies.set('name', 'value', { path: '' })
Cookies.get('name') // => 'value'
Cookies.remove('name', { path: '' })

Note regarding Internet Explorer:

Due to an obscure bug in the underlying WinINET InternetGetCookie implementation, IE’s document.cookie will not return a cookie if it was set with a path attribute containing a filename.

(From Internet Explorer Cookie Internals (FAQ))

This means one cannot set a path using window.location.pathname in case such pathname contains a filename like so: /check.html (or at least, such cookie cannot be read correctly).

In fact, you should never allow untrusted input to set the cookie attributes or you might be exposed to a XSS attack.

domain

A String indicating a valid domain where the cookie should be visible. The cookie will also be visible to all subdomains.

Default: Cookie is visible only to the domain or subdomain of the page where the cookie was created, except for Internet Explorer (see below).

Examples:

Assuming a cookie that is being created on site.com:

Cookies.set('name', 'value', { domain: 'subdomain.site.com' })
Cookies.get('name') // => undefined (need to read at 'subdomain.site.com')

Note regarding Internet Explorer default behavior:

Q3: If I don’t specify a DOMAIN attribute (for) a cookie, IE sends it to all nested subdomains anyway?
A: Yes, a cookie set on example.com will be sent to sub2.sub1.example.com.
Internet Explorer differs from other browsers in this regard.

(From Internet Explorer Cookie Internals (FAQ))

This means that if you omit the domain attribute, it will be visible for a subdomain in IE.

secure

Either true or false, indicating if the cookie transmission requires a secure protocol (https).

Default: No secure protocol requirement.

Examples:

Cookies.set('name', 'value', { secure: true })
Cookies.get('name') // => 'value'
Cookies.remove('name')

Converters

Read

Create a new instance of the api that overrides the default decoding implementation.
All get methods that rely in a proper decoding to work, such as Cookies.get() and Cookies.get('name'), will run the converter first for each cookie.
The returning String will be used as the cookie value.

Example from reading one of the cookies that can only be decoded using the escape function:

document.cookie = 'escaped=%u5317'
document.cookie = 'default=%E5%8C%97'
var cookies = Cookies.withConverter(function (value, name) {
  if (name === 'escaped') {
    return unescape(value)
  }
})
cookies.get('escaped') // 北
cookies.get('default') // 北
cookies.get() // { escaped: '北', default: '北' }

Write

Create a new instance of the api that overrides the default encoding implementation:

Cookies.withConverter({
  read: function (value, name) {
    // Read converter
  },
  write: function (value, name) {
    // Write converter
  }
})

Server-side integration

Check out the Servers Docs

Contributing

Check out the Contributing Guidelines

Security

For vulnerability reports, send an e-mail to jscookieproject at gmail dot com

Manual release steps

  • Increment the "version" attribute of package.json
  • Increment the version number in the src/js.cookie.mjs file
  • If major bump, update jsDelivr CDN major version link on README
  • Commit with the message "Release version x.x.x"
  • Create version tag in git
  • Create a github release and upload the minified file
  • Change the latest tag pointer to the latest commit
    • git tag -f latest
    • git push <remote> :refs/tags/latest
    • git push origin master --tags
  • Release on npm

Supporters

Many thanks to BrowserStack for providing unlimited browser testing free of cost.

Authors