Incorrectly detecting chrome on android as an InApp browser

[reqyo]

Please look into this, seems like being on android and chrome I'm getting it as an inapp browser. Thank you

[aggy-k]

Same here, it's detecting android's chrome as inApp. Here's the User-Agent: Mozilla/5.0 (Linux: Android10; K) AppleWebKit/537.36 (KHTML,like Gecko) Chrome/119.0.0.0 MobileSafari/537.36

I tested this UA against the isInApp regex rules, and it does return FALSE, so not sure why it's returning TRUE for our users. Thank you!

[brunofin]

That's because isInApp matches the string Android as an in app browser, which is wrong: https://github.com/f2etw/detect-inapp/blob/master/src/inapp.js#L42

https://chat.openai.com/share/98549886-db01-4c4c-8c9c-5c3bce26ea42

I guess what could be done is to use the browser function https://github.com/f2etw/detect-inapp/blob/master/src/inapp.js#L26 and manually compare with the returned value.

[brunofin]

here are some user agent strings I got from my own testing. Notice Facebook in-app browser is the only one that contains FB_IAB and Instagram contains Instagram. Those are simple effective methods to test whether the user is accessig from an in-app browser while avoiding false positives such as the one described in this issue.

chrome on linux
    Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

firefox on linux
    Mozilla/5.0 (X11; Linux x86_64; rv:121.0) Gecko/20100101 Firefox/121.0

edge on linux
    Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 Edg/120.0.0.0

chrome on android
    Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Mobile Safari/537.36

firefox on android
    Mozilla/5.0 (Android 14; Mobile; rv:121.0) Gecko/121.0 Firefox/121.0

facebook in app broswer on android
    Mozilla/5.0 (Linux; Android 14; Pixel 6 Build/UQ1A.240105.002; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/120.0.6099.193 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/446.0.0.27.352;]

instagram in app browser on android
    Mozilla/5.0 (Linux; Android 14; Pixel 6 Build/UQ1A.240105.002; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/120.0.6099.193 Mobile Safari/537.36 Instagram 313.0.0.26.328 Android (34/14; 420dpi; 1080x2209; Google/google; Pixel 6; oriole; oriole; en_GB; 554218560)

[brunofin]

one more interesting thing to notice is that on linux browsers even though I am on a Wayland session they still report the string x11.

[shalanah]

Here's what I did: https://github.com/f2etw/detect-inapp/compare/master...shalanah:detect-inapp:shalanah-build

'Android.*(wv|/\\d\\d.0.0.0)',

Feel free to use this in your packages: "detect-inapp": "github:shalanah/detect-inapp#shalanah-build"

I'm also created a debugging page to help test on my devices. https://shalanah.github.io/inapp-debugger/

[brunofin]

I actually ended up removing this package and using a custom solution because none of the other alternative solutions on npm worked properly. Below is the full code. It also works with SSR. This is production tested with a large user base.

/* set of Regex to compare against user agent in order to detect any kind of embedded in app browser */
const IAB = [
  /Instagram/,
  /FB_IAB/,
  /FBAN/,
  /FBIOS/,
  /FBAV/,
  /FBBV/,
  /FBDV/,
  /FBMD/,
  /FBSN/,
  /FBSV/,
  /FBSS/,
  /FBID/,
  /FBLC/,
  /FBOP/,
  /FBRV/,
];

export function isInApp(): boolean {
  if (!isBrowser()) return false;

  const { userAgent } = navigator;
  return IAB.some(value => value.test(userAgent));
}

// nextjs specific implementation of isBrowser
export function isBrowser() {
  if (!process) return false;
  const nextjsProcess = process as NextJSProcess;
  return nextjsProcess.browser === true;
}

This is obviously only checking against Facebook and Instagram at the moment but it works reliably across iOS and Android, old and new versions.

[brunofin]

If you are planning to use this to remove users from in app browsers, the following implementation below works on Android. I am still to find an alternative iOS version for that.

// ...
if (isInApp) {
      // attempt to exit for android;
      const currentLocation = location.origin + location.pathname;
      // @ts-ignore
      window.location = `intent:${currentLocation}#Intent;end`;
// ...

This will open a browser dialog telling users the site is trying to open an app and if they accept. The app is their default browser.

You can aggressively run it on a loop, or first show a full screen modal that cant be closed saying the browser is not supported and make a button with that as a link, either will work and force users out of the in app browsers.

[shalanah]

@brunofin I think a pared down in-app detection is a great idea! Like you noted, I'd need more detection like linkedin, tiktok, etc.

[shalanah]

Also interesting --- would love if Bowser took this on since I'm using it anyway: https://github.com/bowser-js/bowser/pull/452

[shalanah]

@brunofin + all .

I just pushed a fork (with API changes) and created an npm package.

I hope to continue the legacy of detect-inapp and keep it as up-to-date as I can.

To install:

npm install inapp-spy
yarn add inapp-spy

To use (slightly different API)

import InAppSpy from 'inapp-spy';

const {isInApp, appName, appKey} = InAppSpy()

Link to repo: https://github.com/shalanah/inapp-spy

I removed the is mobile, desktop, tablet along with common browsers like "Safari" and "Chrome". I'd recommend bowser to handle that kind of info.