Browserslist

<img width=“120” height=“120” alt=“Browserslist logo by Anton Lovchikov” src=“browserslist.github.io/browserslist/logo.svg” align=“right”>

The config to share target browsers and Node.js versions between different front-end tools. It is used in:

All tools will find target browsers automatically, when you add the following to package.json:

"browserslist": [
    "last 1 version",
    "> 1%",
    "maintained node versions",
    "not dead"
  ]

Or in .browserslistrc config:

# Browsers that we support

last 1 version
> 1%
maintained node versions
not dead

Developers set versions list in queries like last 2 version to be free from updating versions manually. Browserslist will use Can I Use data for this queries.

Browserslist will take queries from tool option, browserslist config, .browserslistrc config, browserslist section in package.json or environment variables.

Browserslist Example shows how every tool uses Browserslist.

Sponsored by Evil Martians

Table of Contents

  1. Tools

  2. Best Practices

  3. Queries

  4. Config File

  5. Shareable Configs

  6. Configuring for Different Environments

  7. Custom Usage Data

  8. JS API

  9. Environment Variables

  10. Cache

Tools

Best Practices

json "browserslist": [ "defaults" ]

Queries

Browserslist will use browsers and Node.js versions query from one of these sources:

  1. browserslist key in package.json file in current or parent directories. We recommend this way.

  2. .browserslistrc config file in current or parent directories.

  3. browserslist config file in current or parent directories.

  4. BROWSERSLIST environment variable.

  5. If the above methods did not produce a valid result Browserslist will use defaults: > 0.5%, last 2 versions, Firefox ESR, not dead.

Query Composition

An or combiner can use the keyword or as well as ,. last 1 version or > 1% is equal to last 1 version, > 1%.

and query combinations are also supported to perform an intersection of the previous query: last 1 version and > 1%.

There is 3 different ways to combine queries as depicted below. First you start with a single query and then we combine the queries to get our final list.

Obviously you can not start with a not combiner, since there is no left-hand side query to combine it with.

| Query combiner type | Illustration | Example | | ——————- | :———-: | ——- | |or/, combiner
(union) | | > .5% or last 2 versions
> .5%, last 2 versions | | and combiner
(intersection) | | > .5% and last 2 versions | | not combiner
(relative complement) | | > .5% and not last 2 versions
> .5% or not last 2 versions
> .5%, not last 2 versions |

A quick way to test your query is to do npx browserslist '> 0.5%, not IE 11' in your terminal.

Full List

You can specify the browser and Node.js versions by queries (case insensitive):

You can add not to any query.

Debug

Run npx browserslist in project directory to see what browsers was selected by your queries.

$ npx browserslist
and_chr 61
and_ff 56
and_qq 1.2
and_uc 11.4
android 56
baidu 7.12
bb 10
chrome 62
edge 16
firefox 56
ios_saf 11
opera 48
safari 11
samsung 5

Browsers

Names are case insensitive:

Config File

package.json

If you want to reduce config files in project root, you can specify browsers in package.json with browserslist key:

{
  "private": true,
  "dependencies": {
    "autoprefixer": "^6.5.4"
  },
  "browserslist": [
    "last 1 version",
    "> 1%",
    "IE 10"
  ]
}

.browserslistrc

Separated Browserslist config should be named .browserslistrc and have browsers queries split by a new line. Comments starts with # symbol:

# Browsers that we support

last 1 version
> 1%
IE 10 # sorry

Browserslist will check config in every directory in path. So, if tool process app/styles/main.css, you can put config to root, app/ or app/styles.

You can specify direct path in BROWSERSLIST_CONFIG environment variables.

Shareable Configs

You can use the following query to reference an exported Browserslist config from another package:

"browserslist": [
    "extends browserslist-config-mycompany"
  ]

For security reasons, external configuration only supports packages that have the browserslist-config- prefix. npm scoped packages are also supported, by naming or prefixing the module with @scope/browserslist-config, such as @scope/browserslist-config or @scope/browserslist-config-mycompany.

If you don’t accept Browserslist queries from users, you can disable the validation by using the dangerousExtend option:

browserslist(queries, { path, dangerousExtend: true })

Because this uses npm's resolution, you can also reference specific files in a package:

"browserslist": [
    "extends browserslist-config-mycompany/desktop",
    "extends browserslist-config-mycompany/mobile"
  ]

When writing a shared Browserslist package, just export an array. browserslist-config-mycompany/index.js:

module.exports = [
  'last 1 version',
  '> 1%',
  'ie 10'
]

Configuring for Different Environments

You can also specify different browser queries for various environments. Browserslist will choose query according to BROWSERSLIST_ENV or NODE_ENV variables. If none of them is declared, Browserslist will firstly look for production queries and then use defaults.

In package.json:

"browserslist": {
    "production": [
      "> 1%",
      "ie 10"
    ],
    "modern": [
      "last 1 chrome version",
      "last 1 firefox version"
    ],
    "ssr": [
      "node 12"
    ]
  }

In .browserslistrc config:

[production]
> 1%
ie 10

[modern]
last 1 chrome version
last 1 firefox version

[ssr]
node 12

Custom Usage Data

If you have a website, you can query against the usage statistics of your site. {browserslist-ga} will ask access to Google Analytics and then generate browserslist-stats.json:

npx browserslist-ga

Or you can use {browserslist-ga-export} to convert Google Analytics data without giving a password for Google account.

You can generate usage statistics file by any other method. File format should be like:

{
  "ie": {
    "6": 0.01,
    "7": 0.4,
    "8": 1.5
  },
  "chrome": {
    …
  },
  …
}

Note that you can query against your custom usage data while also querying against global or regional data. For example, the query > 1% in my stats, > 5% in US, 10% is permitted.

JS API

const browserslist = require('browserslist')

// Your CSS/JS build tool code
function process (source, opts) {
  const browsers = browserslist(opts.overrideBrowserslist, {
    stats: opts.stats,
    path:  opts.file,
    env:   opts.env
  })
  // Your code to add features for selected browsers
}

Queries can be a string "> 1%, IE 10" or an array ['> 1%', 'IE 10'].

If a query is missing, Browserslist will look for a config file. You can provide a path option (that can be a file) to find the config file relatively to it.

Options:

For non-JS environment and debug purpose you can use CLI tool:

browserslist "> 1%, IE 10"

You can get total users coverage for selected browsers by JS API:

browserslist.coverage(browserslist('> 1%'))
//=> 81.4
browserslist.coverage(browserslist('> 1% in US'), 'US')
//=> 83.1
browserslist.coverage(browserslist('> 1% in my stats'), 'my stats')
//=> 83.1
browserslist.coverage(browserslist('> 1% in my stats', { stats }), stats)
//=> 82.2

Or by CLI:

$ browserslist --coverage "> 1%"
These browsers account for 81.4% of all users globally
$ browserslist --coverage=US "> 1% in US"
These browsers account for 83.1% of all users in the US
$ browserslist --coverage "> 1% in my stats"
These browsers account for 83.1% of all users in custom statistics
$ browserslist --coverage "> 1% in my stats" --stats=./stats.json
These browsers account for 83.1% of all users in custom statistics

Environment Variables

If some tool use Browserslist inside, you can change browsers settings by environment variables:

sh BROWSERSLIST="> 5%" gulp css

sh BROWSERSLIST_CONFIG=./config/browserslist gulp css

sh BROWSERSLIST_ENV="development" gulp css

sh BROWSERSLIST_STATS=./config/usage_data.json gulp css

sh BROWSERSLIST_DISABLE_CACHE=1 gulp css

Cache

Browserslist caches the configuration it reads from package.json and browserslist files, as well as knowledge about the existence of files, for the duration of the hosting process.

To clear these caches, use:

browserslist.clearCaches()

To disable the caching altogether, set the BROWSERSLIST_DISABLE_CACHE environment variable.

Security Contact

To report a security vulnerability, please use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.