Environment

Predicates that read navigator, window, and document. Importing them on the server is safe; calling them on the server throws. Don’t put them in module-top-level code if your module runs in SSR.

Predicate	Reads	Quick rule
isMobile.android()	navigator.userAgent	/Android/i
isMobile.ios()	navigator.userAgent	/iPhone|iPad|iPod/i
isMobile.iphone()	navigator.userAgent	/iPhone/i
isMobile.ipad()	navigator.userAgent	/iPad/i
isMobile.ipod()	navigator.userAgent	/iPod/i
isMobile.windows()	navigator.userAgent	/IEMobile/i
isMobile.any()	navigator.userAgent	Logical OR of .android | .ios | .windows
isMac()	navigator.userAgent	/mac/i
isDesktop()	navigator.userAgent	!isMobile.any()
isBrowser(name)	window, navigator, document	Vendor-feature probe by name
isChrome()	window.chrome	webstore || runtime truthy
isFirefox()	window.InstallTrigger	Truthy
isSafari()	navigator.userAgent	/Safari/i AND NOT /Chrome|Chromium|Edg|OPR|Android/i
isOpera()	window.opr?.addons, window.opera, UA	OR of three signals
isIE()	document.documentMode	Truthy
isEdge()	document.documentMode, window.StyleMedia	Not-IE AND has StyleMedia

Patterns

Conditional rendering

import { isMobile } from "@mongez/supportive-is";

function Layout() {
  return isMobile.any() ? <MobileNav /> : <DesktopNav />;
}

Modifier keys

import { isMac } from "@mongez/supportive-is";

const modKey = isMac() ? "Cmd" : "Ctrl";

Touch-aware sizing

import { isMobile } from "@mongez/supportive-is";

const buttonSize = isMobile.any() ? 44 : 32;   // 44px tap target on touch devices

isMobile.any()

The implementation now calls the sibling predicates directly:

any: () => isMobile.android() || isMobile.ios() || isMobile.windows()

No circular reference through the Is namespace — isMobile.any is safe to import on its own without dragging in the rest of the package.

SSR safety

// At module top — safe, never reads navigator
import { isMobile, isMac } from "@mongez/supportive-is";

// At call time — throws on the server because `navigator` is undefined
export function DeviceClass() {
  const device = isMobile.any();   // ← throws in Node without a polyfill
  return device;
}

Gate the call:

const isClient = typeof window !== "undefined";
const device = isClient ? (isMobile.any() ? "mobile" : "desktop") : "unknown";

Or parse request.headers.get("user-agent") on the server with a proper UA parser — these predicates are written for the browser, not for the request-handler path.

Browser-vendor probes

Each vendor probe reads a different bespoke property. All of them are 2018-era hacks; treat the answers as advisory, not authoritative.

• isSafari is userAgent-based: it requires /Safari/i AND excludes Chrome|Chromium|Edg|OPR|Android. Class-based DOM polyfills (happy-dom, JSDOM) no longer trigger a false positive.
• isOpera reads window.opr (guarded with !!w.opr && !!w.opr.addons) plus window.opera and the OPR/ UA token — never touches a bare opr global.

isBrowser(name) vs individual probes

isBrowser is a single entry point that internally calls each probe:

isBrowser("chrome");    // calls isChrome()
isBrowser("firefox");   // calls isFirefox()
isBrowser("safari");    // calls isSafari()
isBrowser("CHROME");    // case-insensitive

Internally, isBrowser evaluates ALL vendor probes every call (it builds a lookup table), so it’s strictly slower than the named predicates. If you only need one vendor, prefer isChrome() over isBrowser("chrome").

Notes

• These predicates work for “what’s running this code right now”, not “what device sent this request”. For server-side UA parsing, use a dedicated parser library on the request headers.
• The IEMobile UA token is from Windows Phone 7+ — modern Windows phones (which mostly don’t exist anyway) won’t match.
• isDesktop() is !isMobile.any() — it doesn’t distinguish “desktop” from “tablet” from “unknown”.