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I had reports from users with Android 8 that my app (that uses back-end feed) does not show content. After investigation I found following Exception happening on Android 8:

08-29 12:03:11.246 11285-11285/ E/: [12:03:11.245, main]: Exception: IOException java.io.IOException: Cleartext HTTP traffic to * not permitted
at com.android.okhttp.HttpHandler$CleartextURLFilter.checkURLPermitted(HttpHandler.java:115)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:458)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:127)
at com.deiw.android.generic.tasks.AbstractHttpAsyncTask.doConnection(AbstractHttpAsyncTask.java:207)
at com.deiw.android.generic.tasks.AbstractHttpAsyncTask.extendedDoInBackground(AbstractHttpAsyncTask.java:102)
at com.deiw.android.generic.tasks.AbstractAsyncTask.doInBackground(AbstractAsyncTask.java:88)
at android.os.AsyncTask$2.call(AsyncTask.java:333)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:764)
(I've removed package name, URL and other possible identifiers)
On Android 7 and lower everything works, I do not set android:usesCleartextTraffic in Manifest (and setting it to true does not help, that is the default value anyway), neither do I use Network Security Information. If I call NetworkSecurityPolicy.getInstance().isCleartextTrafficPermitted(), it returns false for Android 8, true for older version, using the same apk file.
I tried to find some mention of this on Google info about Android O, but without success.
                This happens on an app I maintain because the server redirects from HTTPS to HTTP in some instances.
– Big McLargeHuge
                May 3, 2019 at 15:33
                I am building for API level 30, Android 11, and adding android:usesCleartextTraffic="true" in application tag in manifest works
– masterxilo
                Oct 29, 2022 at 13:50
According to Network security configuration -
Starting with Android 9 (API level 28), cleartext support is disabled
by default.
Also have a look at Android M and the war on cleartext traffic
Codelabs explanation from Google
Option 1 -
First try hitting the URL with https:// instead of http://
Option 2 -
Create file res/xml/network_security_config.xml -
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">api.example.com(to be adjusted)</domain>
    </domain-config>
</network-security-config>
AndroidManifest.xml -
<?xml version="1.0" encoding="utf-8"?>
<manifest ...>
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        android:networkSecurityConfig="@xml/network_security_config"
    </application>
</manifest>
Option 3 -
android:usesCleartextTraffic Doc
AndroidManifest.xml -
<?xml version="1.0" encoding="utf-8"?>
<manifest ...>
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        android:usesCleartextTraffic="true"
    </application>
</manifest>
Also as @david.s' answer pointed out android:targetSandboxVersion can be a problem too -
According to Manifest Docs -
android:targetSandboxVersion
The target sandbox for this app to use. The higher the sandbox version
number, the higher the level of security. Its default value is 1; you
can also set it to 2. Setting this attribute to 2 switches the app to
a different SELinux sandbox. The following restrictions apply to a
level 2 sandbox:
The default value of usesCleartextTraffic in the Network Security    Config is false.
Uid sharing is not permitted.
So Option 4 -
If you have android:targetSandboxVersion in <manifest> then reduce it to 1
AndroidManifest.xml -
<?xml version="1.0" encoding="utf-8"?>
<manifest android:targetSandboxVersion="1">
    <uses-permission android:name="android.permission.INTERNET" />
</manifest>
                @HrishikeshKadam your answer is much appreciated but it seems there must be another step in the most recent release of P? Please see my question stackoverflow.com/questions/51770323/…
– spartygw
                Aug 9, 2018 at 15:04
                What's the point of this Android security feature if every developer going to add android:usesCleartextTraffic="true" ?
– 林果皞
                Jan 24, 2019 at 9:08
                This does not even mention the best solution to this problem: Use HTTPS. The options mentioned in this answer should only be a last resort.
– Christian Brüggemann
                Jan 28, 2019 at 22:47
My problem in Android 9 was navigating on a webview over domains with http
The solution from this answer
<application 
    android:networkSecurityConfig="@xml/network_security_config"
res/xml/network_security_config.xml
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true">
        <trust-anchors>
            <certificates src="system" />
        </trust-anchors>
    </base-config>
</network-security-config>
In the AndroidManifest I found this parameter: 
android:networkSecurityConfig="@xml/network_security_config"
and @xml/network_security_config is defined in network_security_config.xml as: 
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <!--Set application-wide security config using base-config tag.-->
    <base-config cleartextTrafficPermitted="false"/>
</network-security-config>  
just I changed cleartextTrafficPermitted to true
                Not good practise to disable ssl requirements unless this was for internal app of course. But even then should never be disabled.
– c-sharp-and-swiftui-devni
                Sep 20, 2021 at 0:28
You might only want to allow cleartext while debugging, but keep the security benefits of rejecting cleartext in production. This is useful for me because I test my app against a development server that does not support https. Here is how to enforce https in production, but allow cleartext in debug mode:
In build.gradle:
// Put this in your buildtypes debug section:
manifestPlaceholders = [usesCleartextTraffic:"true"]
// Put this in your buildtypes release section
manifestPlaceholders = [usesCleartextTraffic:"false"]
In the application tag in AndroidManifest.xml
android:usesCleartextTraffic="${usesCleartextTraffic}"
                it's only used on api 23+ though. If you want an api independent solution the approved one at: stackoverflow.com/questions/46302058/… is a good option...
– Rik van Velzen
                Mar 1, 2019 at 13:58
                Question: when the app uses web servers that can be http or https by design, will usesCleartextTraffic:"false" even matter if the http urls need to be able to use the web services?  So setting it to true means the https services by default don't send clear text anyway?
– whyoz
                May 31, 2019 at 23:43
Ok, that's ⇒⇒ NOT ⇐⇐ the thousands repeat of add it to your Manifest, but an hint which based on this, but give you additional Benefit (and maybe some Background Info).
Following solution allow you to set the protocol (HTTP / HTTPS) per ENVIRONMENT.
This way you are able to use http for your DEV-Environment, and https for your PRODUCTION-Environment, without the need to change it all the time!
And this is needed, because generally you don't have an https-certificate for your local or dev environment, but it's a MUST-HAVE for production (and maybe for staging) environments.
Android has a kind of overwriting functionality for the src-Directory.
By default, you have
/app/src/main
But you can add additional directories to overwrite your AndroidManifest.xml. Here is how it works:
Create the Directory /app/src/debug
Inside create the AndroidManifest.xml
Inside of this File, you don't have to put all the Rules inside, but only the ones you like to overwrite from your /app/src/main/AndroidManifest.xml
Here an Example how it looks like for the requested CLEARTEXT-Permission:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.yourappname">
    <application
            android:usesCleartextTraffic="true"
            android:name=".MainApplication"
            android:label="@string/app_name"
            android:icon="@mipmap/ic_launcher"
            android:allowBackup="false"
            android:theme="@style/AppTheme">
    </application>
</manifest>
With this knowledge it's now easy as 1,2,3 for you to overload your Permissions depending on your debug | main | release Enviroment.
The big benefit on it... you don't have debug-stuff in your production-Manifest and you keep an straight and easy maintainable structure
                This is definitely the proper solution. Android has added these security settings for a reason, so they should stand. Your solutions allows us to test on local insecure environments, while the production builds will still have the recommended security settings. Thank you!
– Coo
                Apr 23, 2019 at 8:37
                upvoted because it's the right thing to do (in production environments). HTTPS should be the default, not HTTP.
– beetstra
                Feb 18, 2019 at 10:56
                @beetsta You assume that you have full control over what is serving the content. This answer is therefore naive or flippant in nature.
– Martin Price
                Feb 22, 2019 at 13:59
                @beetstra Why should be HTTPS default on a LOCAL machine while debugging? This is so stupid, just another example of Google paternalism. Luckily one can workaround this for debug mode by Tyler's solution.
– Bevor
                Feb 23, 2019 at 18:48
                The answer is ignorant of the question. Unlike people in small companies, sometime you don't have an SSL for every staging server. The answer is as bad as someone correcting grammar in a Facebook post and this doesn't answer the question at all, nor does it fix it.
– Nick Turner
                Aug 27, 2019 at 20:42
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">***Your URL(ex: 127.0.0.1)***</domain>
    </domain-config>
</network-security-config>
In the suggestion provided above I was providing my URL as  http://xyz.abc.com/mno/
I changed that to  xyz.abc.com then it started working.
                This is correct, only FQDN are being supported there, no IP addresses (fixed that above).
– Martin Zeitler
                Nov 17, 2019 at 20:37
It could be useful for someone. 
We recently had the same issue for Android 9, but we only needed to display some Urls within WebView, nothing very special. So adding android:usesCleartextTraffic="true" to Manifest worked, but we didn't want to compromise security of the whole app for this. 
So the fix was in changing links from http to https
                If I only want to display some URLs I don't need a WebView. I just use a TextView. ;) I suppose you mean you show some html pages. Your fix only works if your server offers SSL. You can't simply change the links.
– The incredible Jan
                Nov 22, 2018 at 13:47
                This for sure is the best option whenever possible, but one can't always choose that - either for a performance reason or because simply the resource may not be available in cleartext HTTP.
– Dakatine
                Jan 24, 2019 at 16:04
                "we didn't want to compromise security of the whole app", what security risks can it cause? In my case there is not one URL so i can't add them in manifest.
– Robert Williams
                May 6, 2019 at 12:47
                Hi @RobertWilliams it just means that clear traffic would non encrypted traffic would be allowed. Here is a blogpost medium.com/@son.rommer/…
– El_o.di
                Jun 11, 2019 at 14:44
It was already fixed on RN 0.59.
You can find on upgrade diff from 0.58.6 to 0.59
You can apply it without upgrading you RN versionust follow the below steps:




    

Create files:
android/app/src/debug/res/xml/react_native_config.xml - 
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
  <domain-config cleartextTrafficPermitted="true">
    <domain includeSubdomains="false">localhost</domain>
    <domain includeSubdomains="false">10.0.2.2</domain>
    <domain includeSubdomains="false">10.0.3.2</domain>
  </domain-config>
</network-security-config>
android/app/src/debug/AndroidManifest.xml -
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools">
  <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
  <application tools:targetApi="28"
      tools:ignore="GoogleAppIndexingWarning" 
      android:networkSecurityConfig="@xml/react_native_config" />
</manifest>
Check the accepted answer to know the root cause.
                I use react-native 0.59.5 and i having the same problem, we have to setting manually the AndroidManifest.xml as you suggest.
– Cristian Mora
                May 6, 2019 at 16:19
                Thank you It helped Due to google policy I have to made android:usesCleartextTraffic="false" then I had the problem of running react-native from local in the simulator I did apply the above steps and it worked for me.
– Hidayat Arghandabi
                May 4, 2021 at 10:43
I have removed this line from the android manifest file which is already there
 android:networkSecurityConfig="@xml/network_security_config" 
and added
android:usesCleartextTraffic="true"
this in to application tag in manifest
<application
    android:usesCleartextTraffic="true"
    android:allowBackup="true"
    android:label="@string/app_name"
    android:largeHeap="true"
    android:supportsRtl="true"
    android:theme="@style/AppTheme"
then this error Cleartext HTTP traffic to overlay.openstreetmap.nl not permitted is gone for me in android 9 and 10.I hope this will work for android 8 also if it is helped you don't forget to vote thank you
Adding ...
            android:usesCleartextTraffic="true"
... to your manifest file may appear to fix the problem but it opens a threat to data integrity.
For security reasons I used manifest placeholders with android:usesCleartextTraffic inside the manifest file (like in Option 3 of the accepted answer i.e @Hrishikesh Kadam's response) to only allow cleartext on debug environment. 
Inside my build.gradle(:app) file, I added a manifest placeholder like this:
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        debug {
            manifestPlaceholders.cleartextTrafficPermitted ="true"
Note the placeholder name cleartextTrafficPermitted at this line above
            manifestPlaceholders.cleartextTrafficPermitted ="true"
Then in my Android Manifest, I used the same placeholder ...
AndroidManifest.xml - 
<?xml version="1.0" encoding="utf-8"?>
<manifest ...>
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        android:usesCleartextTraffic="${cleartextTrafficPermitted}"
    </application>
</manifest>
With that, cleartext traffic is only permitted under the debug environment.
You have to set the NSAllowsArbitraryLoads key to YES under NSAppTransportSecurity dictionary in your info.plist file.
<key>NSAppTransportSecurity</key>
  <key>NSAllowsArbitraryLoads</key>
  <true/>
</dict>
Okay, I have figured this out. It is due to the Manifest parameter android:targetSandboxVersion="2", that I have added because we also have Instant App version - it should make sure than once user upgrades from Instant App to regular app, he will not loose his data with the transfer. However as the vague description suggest:
Specifies the target sandbox this app wants to use. Higher sanbox versions will have increasing levels of security.
The default value of this attribute is 1.
It obviously also adds new level of security policy, at least on Android 8.
To apply these various answers to Xamarin.Android, you can use class and assembly level Attributes vs. manually editing the AndroidManifest.xml
Internet permission of course is needed (duh..):
[assembly: UsesPermission(Android.Manifest.Permission.Internet)]
Note: Typically assembly level attributes are added to your AssemblyInfo.cs file, but any file, below the using and above the namespace works.
Then on your Application subclass (create one if needed), you can add NetworkSecurityConfig with a reference to an Resources/xml/ZZZZ.xml file:
#if DEBUG
[Application(AllowBackup = false, Debuggable = true, NetworkSecurityConfig = "@xml/network_security_config")]
#else
[Application(AllowBackup = true, Debuggable = false, NetworkSecurityConfig = "@xml/network_security_config"))]
#endif
public class App : Application
    public App(IntPtr javaReference, Android.Runtime.JniHandleOwnership transfer) : base(javaReference, transfer) { }
    public App() { }
    public override void OnCreate()
        base.OnCreate();
Create a file in the Resources/xml folder (create the xml folder if needed).
Example xml/network_security_config file, adjust as needed (see other answers)
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
          <domain includeSubdomains="true">www.example.com</domain>
          <domain includeSubdomains="true">notsecure.com</domain>
          <domain includeSubdomains="false">xxx.xxx.xxx</domain>
    </domain-config>
</network-security-config>
You can also use the UsesCleartextTraffic parameter on the ApplicationAttribute:
#if DEBUG
[Application(AllowBackup = false, Debuggable = true, UsesCleartextTraffic = true)]
#else
[Application(AllowBackup = true, Debuggable = false, UsesCleartextTraffic = true))]
#endif
                How does this work if you are not on a doamin and on a local host address of 192.168 the applicaiton will not be live out on the internet but a local network
– c-sharp-and-swiftui-devni
                Jun 12, 2019 at 21:09
While the working answer, for me, was this by @PabloCegarra:
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true">
        <trust-anchors>
            <certificates src="system" />
        </trust-anchors>
    </base-config>
</network-security-config>
You may receive a security warning regarding the cleartextTrafficPermitted="true"
If you know the domains to 'white list' you should mix both accepted answer and the above one:
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="false">
        <trust-anchors>
            <certificates src="system" />
        </trust-anchors>
    </base-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">books.google.com</domain>
        <trust-anchors>
            <certificates src="system" />
        </trust-anchors>
    </domain-config>
</network-security-config>
This code is working for me, but my app needs to retrieve data from books.google.com only.
By this way the security warning disappears.
I am also got the same "Cleartext HTTP traffic not permitted" error while developing my Application. I am using Retrofit2 for network calls in my application and I have two project environments(dev & production). My Production domain is having SSL certificate with HTTPS calls and dev won't have https. The configuration is added in the build flavors. But when I change to dev, this issue will trigger. So I have added below-solution for that.
I have added cleartext traffic in the manifest
 android:usesCleartextTraffic="true"
Then I have added a connection spec in the retrofit configuration class OKHttp creation time.
 .connectionSpecs(CollectionsKt.listOf(ConnectionSpec.MODERN_TLS, ConnectionSpec.CLEARTEXT))
Complete OkHttpClient creation is given below
OkHttpClient okHttpClient = new OkHttpClient.Builder()
        .readTimeout(10, TimeUnit.SECONDS)
        .connectTimeout(10, TimeUnit.SECONDS)
        .cache(null)
        .connectionSpecs(CollectionsKt.listOf(ConnectionSpec.MODERN_TLS, ConnectionSpec.CLEARTEXT))
        .addInterceptor(new NetworkInterceptor(context))
        .addInterceptor(createLoggingInterceptor())
        .addInterceptor(createSessionExpiryInterceptor())
        .addInterceptor(createContextHeaderInterceptor())
        .build();
Update December 2019 ionic - 4.7.1
<manifest xmlns:tools=“http://schemas.android.com/tools”>
<application android:usesCleartextTraffic=“true” tools:targetApi=“28”>
Please add above content in android manifest .xml file
Previous Versions of ionic
Make sure you have the following in your config.xml in Ionic Project:
<edit-config file="app/src/main/AndroidManifest.xml" mode="merge" target="/manifest/application" xmlns:android="http://schemas.android.com/apk/res/android">
            <application android:networkSecurityConfig="@xml/network_security_config" />
            <application android:usesCleartextTraffic="true" />
        </edit-config>
Run ionic Cordova build android. It creates Android folder under Platforms
Open Android Studio and open the Android folder present in our project
project-platforms-android. Leave it for few minutes so that it builds the gradle
After gradle build is finished we get some errors for including minSdVersion in manifest.xml.
Now what we do is just remove <uses-sdk android:minSdkVersion="19" /> from manifest.xml.
Make sure its removed from both the locations:
app → manifests → AndroidManifest.xml.
CordovaLib → manifests → AndroidManifest.xml.
Now try to build the gradle again and now it builds successfully

Make sure you have the following in Application tag in App → manifest → Androidmanifest.xml:
<application
android:networkSecurityConfig="@xml/network_security_config"  android:usesCleartextTraffic="true" >
Open network_security_config (app → res → xml → network_security_config.xml).
Add the following code:
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">xxx.yyyy.com</domain>
    </domain-config>
</network-security-config>
Here xxx.yyyy.com is the link of your HTTP API. Make sure you don't include any Http before the URL.
Note: Now build the app using Android Studio (Build -- Build Bundle's/APK -- Build APK) and now you can use that App and it works fine in Android Pie. If you try to build app using ionic Cordova build android it overrides all these settings so make sure you use Android Studio to build the Project.
If you have any older versions of app installed, Uninstall them and give a try or else you will be left with some error:
  
App not Installed
                ionic? Cordova? So it isn't a normal Android build, but a framework to build native apps with front end tech instead.
– Weekend
                Nov 15, 2019 at 3:03
                Ionic provides u the webivew implementation in android app and Cordova helps u to access android native features like microphone, camera.
– Gvs Akhil
                Nov 15, 2019 at 3:08
I would suggest to add both dev and prod network configs:
add res/xml/network_security_config_dev.xml
<?xml version="1.0" encoding="utf-8"?>
 <network-security-config>
    <domain-config cleartextTrafficPermitted="true">
    <domain includeSubdomains="true">10.0.2.2</domain>
 </domain-config>
</network-security-config>
addres/xml/network_security_config_prod.xml
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
  <domain-config cleartextTrafficPermitted="false">
    <domain includeSubdomains="true">yourdomain.com</domain>
  </domain-config>
</network-security-config>
under Gradle Scripts (in android studio), find build.gradle (android.app) and look for buildTypes: release and debug (create if not exists):
buildTypes {
release {
    minifyEnabled false
    manifestPlaceholders.securityConfig = "@xml/network_security_config_prod"
 debug {
    manifestPlaceholders.securityConfig = "@xml/network_security_config_dev"
in AndroidManifest.xml use securityConfig placeholder as following (which was  defined in build.gradle):
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:networkSecurityConfig="${securityConfig}"   <------- here
                Why do I see this answer first? No mention of security concerns, nothing! I mean one cannot simply disable a security feature that prevents MITM, eavesdropping, etc. Your answer correctly solves the OP problem, though.
– Kaymaz
                Mar 24 at 8:34
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">192.168.0.101</domain>
    </domain-config>
</network-security-config>
Open AndroidManifests.xml :
 android:usesCleartextTraffic="true" //Add this line in your manifests
<application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:usesCleartextTraffic="true"
        android:theme="@style/AppTheme">
 cleartext support is disabled by default.Android in 9 and above
 Try This one I hope It will work fine
1 Step:->  add inside android build gradle (Module:App)
            useLibrary 'org.apache.http.legacy'
  android {
               compileSdkVersion 28
              useLibrary 'org.apache.http.legacy'
Then 2 Step:-> manifest 
   add inside manifest   application tag
<application
    android:networkSecurityConfig="@xml/network_security_config">//add drawable goto Step 4
   // Step --->3  add to top this line  
     <uses-library
        android:name="org.apache.http.legacy"
        android:required="false" />
</application>
//Step 4-->> Create Drawable>>Xml file>>name as>> network_security_config.xml
   <?xml version="1.0" encoding="utf-8"?>
   <network-security-config>
      <base-config cleartextTrafficPermitted="true">
        <trust-anchors>
           <certificates src="system" />
        </trust-anchors>
      </base-config>
    </network-security-config>
                @Shadow  <base-config cleartextTrafficPermitted="true">         <trust-anchors>            <certificates src="system" />         </trust-anchors>       </base-config>   <domain-config cleartextTrafficPermitted="true">         <domain includeSubdomains="true">www.yourwebsidedomain.com</domain>     </domain-config>
– Ashif
                Mar 16, 2020 at 11:58
                No!! Again you are saying in application side. I am asking how to change in framework/<> folder class?
– Shadow
                Mar 18, 2020 at 10:44
Put following into your resources/android/xml/network_security_config.xml :
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true" />
</network-security-config>
This solves Failed to load resource: net::ERR_CLEARTEXT_NOT_PERMITTED problem on Android for Cordova / Ionic.
                myWebView.loadUrl("www.site.com");   is also works for webmasters don't have SSL as HTTPS but have HTTP only. Might get blank page but.
– Bay
                Sep 6, 2019 at 11:03
                if given url is worked in your web browser then you can use in your webview. otherwise you can see this error.
– Mayuresh Deshmukh
                Sep 6, 2019 at 11:33
                I know sometimes it gives an error, but most of the time I see blank page even run.javascript is "true" and I can access the website correctly. I don't know why I see blank page, also I set zoom-able true.
– Bay
                Sep 6, 2019 at 22:31
For Xamarin.Android developers make sure HttpClient implementation and SSL/TLS is set to Default.
It can be found under Andorid Options -> Advanced Android Options.
This is done for security reasons, you should always prefer to use HTTPS (HTTP Secure) where possible.

You can read more about it here  
There are multiple solutions for this issue depending on your condition.  
If you are trying to communicate with a first party service, IE: your own web server
Server side: You should add HTTPS support to that server and use HTTPS instead of HTTP. These days you can even do it for free using services like LetsEncrypt and others

Client side: If you are using the HttpURLConnection from the java.net package you can switch to HttpsURLConnection of the java.net.ssl package, it has a similar if not identical API, so the switch should be effortless.
If you are using a third party service, like Google, Facebook, a weather service, etc.
In case that the service you are communicating with supports HTTPS (which it most likely does) you can just change your request URL from http://abc.xyz to https://abc.xyz.  
As a last resort, if the third party service that you want to communicate with does not support HTTPS or any other form of secure communication, you can use this answer, but again, this is not recommended as it defeats the purpose of this much needed security feature.
If you are using ionic and getting this error during native http plugin, following fix needs to be done-
goto resources/android/xml/network_security_config.xml
Change it to-
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">localhost</domain>
        <domain includeSubdomains="true">api.example.com(to be adjusted)</domain>
    </domain-config>
</network-security-config>
That worked for me!
I using Cordova 8 with cordova-plugin-whitelist 1.3.4
and it default configuration my app no access to internet and i only add a parameter in the manifest.xml -> android:usesCleartextTraffic="true"
The path of mainfest changed in Cordova 8: platform/android/app/src/main/AndroidManifest.xml. 
 <?xml version='1.0' encoding='utf-8'?>
    <manifest android:hardwareAccelerated="true" android:versionCode="10000" android:versionName="1.0.0" package="io.cordova.hellocordova" xmlns:android="http://schemas.android.com/apk/res/android">
        <supports-screens android:anyDensity="true" android:largeScreens="true" android:normalScreens="true" android:resizeable="true" android:smallScreens="true" android:xlargeScreens="true" />
        <application 
android:hardwareAccelerated="true" 
android:icon="@mipmap/ic_launcher" 
android:label="@string/app_name" 
android:supportsRtl="true" 
android:usesCleartextTraffic="true">
            <activity android:configChanges="orientation|keyboardHidden|keyboard|screenSize|locale|smallestScreenSize|screenLayout|uiMode" android:label="@string/activity_name" android:launchMode="singleTop" android:name="MainActivity" android:theme="@android:style/Theme.DeviceDefault.NoActionBar" android:windowSoftInputMode="adjustResize">
                <intent-filter android:label="@string/launcher_name">
                    <action android:name="android.intent.action.MAIN" />
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>
        </application>
        <uses-permission android:name="android.permission.INTERNET" />
        <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    </manifest>
this is a real stupid because it obvious that your app need access to internet....
videoView can't open this video Online video
Create file res/xml/network_security_config.xml
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true">
        <trust-anchors>
            <certificates src="system" />
        </trust-anchors>
    </base-config>
</network-security-config>
New in the AndroidManifest.xml file under application:
android:networkSecurityConfig="@xml/network_security_config"
https://techprogrammingideas.blogspot.com/2021/02/android-code-for-displaying-video-with.html
https://youtu.be/90hWWAqfdUU
Upgrade to React Native 0.58.5 or higher version.
They have includeSubdomain in their config files in RN 0.58.5.
ChangeLog
In Rn 0.58.5 they have declared network_security_config with their server domain. Network security configuration allows an app to permit cleartext traffic from a certain domain. So no need to put extra effort by declaring android:usesCleartextTraffic="true" in the application tag of your manifest file. It will be resolved automatically after upgrading the RN Version.
After changed API version 9.0 getting the error Cleartext HTTP traffic to YOUR-API.DOMAIN.COM not permitted (targetSdkVersion="28"). in xamarin, xamarin.android and android studio.
Two steps to solve this error in xamarin, xamarin.android and android studio.
Step 1: Create file resources/xml/network_security_config.xml
In network_security_config.xml
<?xml version="1.0" encoding="utf-8" ?>
<network-security-config>
  <domain-config cleartextTrafficPermitted="true">
    <domain includeSubdomains="true">mobapi.3detrack.in</domain>
  </domain-config>
</network-security-config>
Step 2: update AndroidManifest.xml -
Add android:networkSecurityConfig="@xml/network_security_config" on application tag.
<application android:label="your App Name" android:icon="@drawable/icon" android:networkSecurityConfig="@xml/network_security_config">