browserslist-useragent-regexp

A utility to compile browserslist query to a regex to test browser useragent. Simplest example: you can detect supported browsers on client-side.

1. Create .browserslistrc config, for example like this:

last 2 versions
not dead
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2. Add script to package.json:

{
  "scripts": {
    "supportedBrowsers": "echo \"export default $(browserslist-useragent-regexp --allowHigherVersions);\" > supportedBrowsers.js"
  }
}
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{
  "scripts": {
    "supportedBrowsers": "(echo export default && browserslist-useragent-regexp --allowHigherVersions) > supportedBrowsers.js"
  }
}
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3. Run this script, to compile regex:

pnpm supportedBrowsers
# or
npm run supportedBrowsers
# or
yarn supportedBrowsers
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supportedBrowsers.js:

export default /Edge?\/(10[5-9]|1[1-9]\d|[2-9]\d\d|\d{4,})(\.\d+|)(\.\d+|)|Firefox\/(10[4-9]|1[1-9]\d|[2-9]\d\d|\d{4,})\.\d+(\.\d+|)|Chrom(ium|e)\/(10[5-9]|1[1-9]\d|[2-9]\d\d|\d{4,})\.\d+(\.\d+|)|Maci.* Version\/(15\.([6-9]|\d{2,})|(1[6-9]|[2-9]\d|\d{3,})\.\d+)([,.]\d+|)( Mobile\/\w+|) Safari\/|Chrome.+OPR\/(9\d|\d{3,})\.\d+\.\d+|(CPU[ +]OS|iPhone[ +]OS|CPU[ +]iPhone|CPU IPhone OS|CPU iPad OS)[ +]+(15[._]([6-9]|\d{2,})|(1[6-9]|[2-9]\d|\d{3,})[._]\d+)([._]\d+|)|Opera Mini|Android:?[ /\-](10[6-9]|1[1-9]\d|[2-9]\d{2}|\d{4,})(\.\d+|)(\.\d+|)|Mobile Safari.+OPR\/(6[4-9]|[7-9]\d|\d{3,})\.\d+\.\d+|Android.+Firefox\/(10[5-9]|1[1-9]\d|[2-9]\d\d|\d{4,})\.\d+(\.\d+|)|Android.+Chrom(ium|e)\/(10[6-9]|1[1-9]\d|[2-9]\d\d|\d{4,})\.\d+(\.\d+|)|Android.+(UC? ?Browser|UCWEB|U3)[ /]?(13\.([4-9]|\d{2,})|(1[4-9]|[2-9]\d|\d{3,})\.\d+)\.\d+|SamsungBrowser\/(1[7-9]|[2-9]\d|\d{3,})\.\d+|Android.+MQQBrowser\/(13(\.([1-9]|\d{2,})|)|(1[4-9]|[2-9]\d|\d{3,})(\.\d+|))(\.\d+|)|K[Aa][Ii]OS\/(2\.([5-9]|\d{2,})|([3-9]|\d{2,})\.\d+)(\.\d+|)/;
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4. Import regex from created file:

import supportedBrowsers from './supportedBrowsers.js';

if (supportedBrowsers.test(navigator.userAgent)) {
  alert('Your browser is supported.');
}
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Install

pnpm add -D browserslist-useragent-regexp
# or
npm i -D browserslist-useragent-regexp
# or
yarn add -D browserslist-useragent-regexp
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Why?

As was written in article "Smart Bundling: Shipping legacy code to only legacy browsers": you can determinate, which bundle you should give to browser from server with browserslist-useragent. But in this case you must have your own server with special logic. Now, with browserslist-useragent-regexp, you can move that to client-side.

Development was inspired by this proposal from Mathias Bynens.

How to make differential resource loading and other optimizations with browserslist-useragent-regexp you can read in article "Speed up with Browserslist".

Demo (sources, build script).

Also, testing useragents using generated regex is faster than using the matchesUA method from browserslist-useragent.

CLI

pnpm browserslist-useragent-regexp [query] [...options]
# or
npx browserslist-useragent-regexp [query] [...options]
# or
yarn exec -- browserslist-useragent-regexp [query] [...options]
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Also, short alias is available:

pnpm bluare [query] [...options]
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JS API basics

Module exposes two main methods:

getUserAgentRegexes(options)

Compile browserslist query to regexes for each browser.

getUserAgentRegex(options)

Compile browserslist query to one regex.

Description of all methods you can find in Documentation.

Options

Any of the browserslist API options may also be provided.

Regex info object

Other

• Supported browsers
• Notes
• When querying for modern browsers