Getting started

These docs describe the 1.0.0-beta API. Install the beta release to use the factory and extensions.

npm

npm install undevice@beta

pnpm

pnpm add undevice@beta

yarn

yarn add undevice@beta

bun

bun add undevice@beta

First detection

Create a detector once, then pass each incoming request's headers to detect():

import { undevice } from "undevice";

const { detect } = undevice();
const device = detect({ headers: request.headers });

device.isMobile;
device.isTablet;
device.isDesktop;

undevice() returns a frozen object with a detect method. Each call to detect() returns a new frozen UndeviceResult with detection flags.

The library does not mutate input data or implicitly access request context or browser globals.

User-Agent

In the browser, pass navigator.userAgent:

import { undevice } from "undevice";

const { detect } = undevice();
const device = detect({ userAgent: navigator.userAgent });

To override the User-Agent:

const device = detect({
  headers: request.headers,
  userAgent: customUserAgent,
});

For SSR, reuse the server's result on the client to avoid hydration mismatches.