检测android webview

Question

I have an html-javascript page, and I need to detect whenever it open on web view (Like inside facebook webview, twitter webview, etc.), and if it a webview - display another content.

Note: I do not control the third-party Android apps, so I cannot make changes to their code.

I already found a way to detect an IOS webview (Found it on stackoverflow):

var isIosWebview =/(iPhone|iPod|iPad).*AppleWebKit(?!.*Safari)/i.test(navigator.userAgent)

Now I'm looking for a javascript code that can detect Android web view.

Help?

Answer 1

You can't detect it by only using the user agent string, as any app that uses WebView can set the UA string to anything it wants.

If you still insist on using the UA string, this is the explanation of the official docs: initially, Chromium-based WebView was using .0.0.0 as Chrome version suffix; in the newer versions ; wv ; wv was added into the platform part of the UA string. Note that pre-KitKat WebViews didn't have the Chrome part. See older posts about that: Android, webview user agent vs browser user agent

Another hint of WebView involvement is presence of X-Requested-With HTTP header with an application package name. Note that this header is also set by XMLHttpRequest, so you need to look for the actual value of the header.

The statement that WebView doesn't support iframes is not correct.

Answer 2

The info others provided in this thread gave me what I needed to solve this problem in my case. For others, here is the resulting JS regex which represents the detection described in the accepted answer:

/(Version\/\d+.*\/\d+.0.0.0 Mobile|; ?wv|(iPhone|iPod|iPad).*AppleWebKit(?!.*Safari))/i.test(navigator.userAgent)

The regex includes cases for old Android, new Android, iOS versions.

Answer 3

I know how to do it. It is very simple. Because there is an object used by Android web view to trigger functions in its Android app via javascript. So in your js code you can use:

if (typeof Android === "undefined") {
    // do something if is NOT a web view
} else {
    // do something else if is a web view
}

Answer 4

I needed to detect if the browser was an Android WebView without using the User-Agent (since it can be spoofed), and without reading the Headers server-side.

It appears they were quite sneaky in hiding this, but you can check if the window has a property named "Android " (with a space at the end). This appears to be true only when being used as a WebView inside an app, and not in Chrome on the same device.

const isAndroidWebView = window.hasOwnProperty('Android ')

Disclaimer: I have only verified this on a Pixel 3 running Android 10, and a Nokia 6 running Android 9. Please comment if this does or doesn't work for your device.