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Browserslist


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

Autoprefixer
Babel
postcss-preset-env
eslint-plugin-compat
stylelint-no-unsupported-browser-features
postcss-normalize
obsolete-webpack-plugin

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

  1. ``` json
  2.   "browserslist": [
  3.     "defaults and supports es6-module",
  4.     "maintained node versions"
  5.   ]
  6. ```

Or in .browserslistrc config:

  1. ``` yaml
  2. # Browsers that we support

  4. defaults and supports es6-module
  5. maintained node versions
  6. ```

Developers set their version lists using queries like last 2 versions to be free from updating versions manually. Browserslist will use caniuse-lite with Can I Use data for this queries.

You can check how config works at our playground: browsersl.ist

browsersl.ist website

Table of Contents


Tools
Best Practices
Queries
Config File
Shareable Configs
Configuring for Different Environments
Custom Usage Data
JS API
Environment Variables
Cache
Security Contact
For Enterprise

Sponsors


Browserslist needs your support. We are accepting donations at Open Collective.

Tools


Analyze your Browserslist Config


Run npx browserslist in your project directory to see project’s target browsers. This CLI tool is built-in and available in any project with Autoprefixer.
browserslist-lint checks your config for popular mistakes.

Update caniuse-lite


update-browserslist-db is a CLI tool to update browsers DB for queries like last 2 version or >1%.
browserslist-update-action is a GitHub Action to automatically runs update-browserslist-db and proposes a pull request to merge updates.

Show “We do not support your browser” Banner


browserslist-useragent-regexp compiles Browserslist query to a RegExp to test browser useragent.
browserslist-useragent-ruby is a Ruby library to checks browser by user agent string to match Browserslist.

Get Statistics for >5% in my stats:


browserslist-ga and browserslist-ga-export download your website browsers statistics to use it in > 0.5% in my stats query.
browserslist-new-relic generate a custom usage data file for Browserslist
browserslist-adobe-analytics use Adobe Analytics data to target browsers. from your New Relic Browser data.

Others


browserslist-rs is a Browserslist port to Rust.
browserslist-browserstack runs BrowserStack tests for all browsers in Browserslist config.

Text Editors


These extensions will add syntax highlighting for .browserslistrc files.

VS Code
Vim
WebStorm

Best Practices


There is a defaults query, which gives a reasonable configuration for most users:

  1. ``` json
  2.   "browserslist": [
  3.     "defaults"
  4.   ]
  5. ```

If you want to change the default set of browsers, we recommend including last 2 versions, not dead, > 0.2%. This is because last n versions on its own does not add popular old versions, while only using a percentage of usage numbers above 0.2% will in the long run make popular browsers even more popular. We might run into a monopoly and stagnation situation, as we had with Internet Explorer 6. Please use this setting with caution.

Select browsers directly (last 2 Chrome versions ) only if you are making a web app for a kiosk with one browser. There are a lot of browsers on the market. If you are making general web app you should respect browsers diversity.

Don’t remove browsers just because you don’t know them. Opera Mini has 100 million users in Africa and it is more popular in the global market than Microsoft Edge. Chinese QQ Browsers has more market share than Firefox and desktop Safari combined.

Queries


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

.browserslistrc config file in current or parent directories.
browserslist key in package.json file in current or parent directories.
browserslist config file in current or parent directories.
BROWSERSLIST environment variable.
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 all the previous queries: last 1 version or chrome > 75 and > 1% will select (browser last version or Chrome since 76 ) and more than 1% marketshare.

There are 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 notstart with a not combiner, since there is no left-hand side query to combine it with. The left-hand is always resolved as and combiner even if or is used (this is an API implementation specificity).

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) These three are equivalent to one another: > .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 '> 0.3%, not dead' in your terminal.

Full List


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

defaults : Browserslist’s default browsers (> 0.5%, last 2 versions, Firefox ESR, not dead ).
By usage statistics:
> 5% : browsers versions selected by global usage statistics. >=, < and <= work too.
> 5% in US : uses USA usage statistics. It accepts two-letter country code.
> 5% in alt-AS : uses Asia region usage statistics. List of all region codes can be found at caniuse-lite/data/regions.
> 5% in my stats : uses custom usage data.
> 5% in browserslist-config-mycompany stats : uses custom usage data from browserslist-config-mycompany/browserslist-stats.json.
cover 99.5% : most popular browsers that provide coverage.
cover 99.5% in US : same as above, with two-letter country code.
cover 99.5% in my stats : uses custom usage data.

Last versions:
last 2 versions : the last 2 versions for eachbrowser.
last 2 Chrome versions : the last 2 versions of Chrome browser.
last 2 major versions or last 2 iOS major versions : all minor/patch releases of last 2 major versions.

dead : browsers without official support or updates for 24 months. Right now it is IE 11, IE_Mob 11, BlackBerry 10, BlackBerry 7, Samsung 4, OperaMobile 12.1 and all versions of Baidu.
Node.js versions:
node 10 and node 10.4 : selects latest Node.js 10.x.x or 10.4.x release.
last 2 node versions : select 2 latest Node.js releases.
last 2 node major versions : select 2 latest major-version Node.js releases.
current node : Node.js version used by Browserslist right now.
maintained node versions : all Node.js versions, which are still maintained by Node.js Foundation.

Browsers versions:
iOS 7 : the iOS browser version 7 directly. Note, that op_mini has special version all.
Firefox > 20 : versions of Firefox newer than 20. >=, < and <= work too. It also works with Node.js.
ie 6-8 : selects an inclusive range of versions.
Firefox ESR : the latest Firefox Extended Support Release.
PhantomJS 2.1 and PhantomJS 1.9 : selects Safari versions similar to PhantomJS runtime.

extends browserslist-config-mycompany : take queries from browserslist-config-mycompany npm package.
supports es6-module : browsers with support for specific features. es6-module here is the feat parameter at the URL of the Can I Use page. A list of all available features can be found at caniuse-lite/data/features.
browserslist config : the browsers defined in Browserslist config. Useful in Differential Serving to modify user’s config like browserslist config and supports es6-module.
since 2015 or last 2 years : all versions released since year 2015 (also since 2015-03 and since 2015-03-10 ).
unreleased versions or unreleased Chrome versions : alpha and beta versions.
not ie <= 8 : exclude IE 8 and lower from previous queries.

You can add not to any query.

Grammar Definition


There is a grammar specification about the query syntax, which may be helpful if you're implementing a parser or something else.

Debug


Run npx browserslist in a project directory to see which browsers were selected by your queries.

  1. ``` shell
  2. $ npx browserslist
  3. and_chr 61
  4. and_ff 56
  5. and_qq 1.2
  6. and_uc 11.4
  7. android 56
  8. baidu 7.12
  9. bb 10
  10. chrome 62
  11. edge 16
  12. firefox 56
  13. ios_saf 11
  14. opera 48
  15. safari 11
  16. samsung 5
  17. ```

Browsers


The following table maps browser names & their target devices into identifiers used by browserslist.

Browser Name Desktop Android iOS Other Mobile
:--- :--- :--- :--- :---
Android (WebView) Android
Baidu Baidu
BlackBerry BlackBerry bb
Chrome Chrome ChromeAndroid and_chr ↪︎ ios_saf2
Edge Edge ↪︎ and_chr ↪︎ ios_saf2
Electron Electron
Firefox Firefox ff FirefoxAndroid and_ff ↪︎ ios_saf2
Internet Explorer Explorer ie ie_mob
Node.js Node
KaiOS Browser kaios
Opera Opera op_mob 1 ↪︎ ios_saf2
Opera Mini3 OperaMini
QQ browser and_qq
Safari Safari iOS ios_saf
Samsung Internet Samsung
UC Browser UCAndroid and_uc

↪︎ name implies that the browser uses the same engine captured by name
1* Opera Mobile ≈ Chrome Android
2* All iOS browsers use WebKit
3* Opera Mini has 2 modes “Extreme” and “High” for data saving. op_mini targets at the “Extreme” one. “High” is compatible with the normal Opera Mobile.

Config File


package.json


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

  1. ``` json
  2. {
  3.   "private": true,
  4.   "dependencies": {
  5.     "autoprefixer": "^6.5.4"
  6.   },
  7.   "browserslist": [
  8.     "last 1 version",
  9.     "> 1%",
  10.     "not dead"
  11.   ]
  12. }
  13. ```

.browserslistrc


Separated Browserslist config should be named .browserslistrc and have browsers queries split by a new line. Each line is combined with the or combiner. Comments starts with # symbol:

  1. ``` yaml
  2. # Browsers that we support

  4. last 1 version
  5. > 1%
  6. not dead # no browsers without security updates
  7. ```

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:

  1. ``` json
  2.   "browserslist": [
  3.     "extends browserslist-config-mycompany"
  4.   ]
  5. ```

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 or BROWSERSLIST_DANGEROUS_EXTEND environment variable.

  1. ``` shell
  2. BROWSERSLIST_DANGEROUS_EXTEND=1 npx webpack
  3. ```

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

  1. ``` json
  2.   "browserslist": [
  3.     "extends browserslist-config-mycompany/desktop",
  4.     "extends browserslist-config-mycompany/mobile"
  5.   ]
  6. ```

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

  1. ``` js
  2. module.exports = [
  3.   'last 1 version',
  4.   '> 1%',
  5.   'not dead'
  6. ]
  7. ```

You can also include a browserslist-stats.json file as part of your shareable config at the root and query it using > 5% in browserslist-config-mycompany stats. It uses the same format as extends and the dangerousExtend property as above.

You can export configs for different environments and select environment by BROWSERSLIST_ENV or env option in your tool:

  1. ``` js
  2. module.exports = {
  3.   development: [
  4.     'last 1 version'
  5.   ],
  6.   production: [
  7.     'last 1 version',
  8.     '> 1%',
  9.     'not dead'
  10.   ]
  11. }
  12. ```

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 :

  1. ``` js
  2.   "browserslist": {
  3.     "production": [
  4.       "> 1%",
  5.       "not dead"
  6.     ],
  7.     "modern": [
  8.       "last 1 chrome version",
  9.       "last 1 firefox version"
  10.     ],
  11.     "ssr": [
  12.       "node 12"
  13.     ]
  14.   }
  15. ```

In .browserslistrc config:

  1. ``` ini
  2. [production]
  3. > 1%
  4. not dead

  6. [modern]
  7. last 1 chrome version
  8. last 1 firefox version

  10. [ssr]
  11. node 12
  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 :

  1. ``` sh
  2. npx browserslist-ga

  4. ```

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:

  1. ``` js
  2. {
  3.   "ie": {
  4.     "6": 0.01,
  5.     "7": 0.4,
  6.     "8": 1.5
  7.   },
  8.   "chrome": {
  9.     …
  10.   },
  11.   …
  12. }
  13. ```

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


  1. ``` js
  2. const browserslist = require('browserslist')

  4. // Your CSS/JS build tool code
  5. function process (source, opts) {
  6.   const browsers = browserslist(opts.overrideBrowserslist, {
  7.     stats: opts.stats,
  8.     path:  opts.file,
  9.     env:   opts.env
  10.   })
  11.   // Your code to add features for selected browsers
  12. }
  13. ```

Queries can be a string "> 1%, not dead" or an array ['> 1%', 'not dead'].

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:

path : file or a directory pa