React Native fetch() Network Request Failed

Question

When I create a brand new project using react-native init (RN version 0.29.1) and put a fetch in the render method to the public facebook demo movie API, it throws a Network Request Failed. There is a very useless stack trace and I can't debug network requests in the chrome console. Here is the fetch I'm sending:

fetch('http://facebook.github.io/react-native/movies.json')
      .then((response) => response.json())
      .then((responseJson) => {
        return responseJson.movies;
      })
      .catch((error) => {
        console.error(error);
      });

Answer 1

The problem here is that iOS does not allow HTTP requests by default, only HTTPS. If you want to enable HTTP requests add this to your info.plist:

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSAllowsArbitraryLoads</key>
    <true/>
</dict>

Answer 2

I was using localhost for the address, which was obviously wrong. After replacing it with the IP address of the server (in the network that emulator is), it worked perfectly.

Edit

In Android Emulator, the address of the development machine is 10.0.2.2. More explanation here

For Genymotion, the address is 10.0.3.2. More info here

Answer 3

Not recommended to allow all domains for http. Make an exception for just the necessary domains.

Source: Configuring App Transport Security Exceptions in iOS 9 and OSX 10.11

Add the following to the info.plist file of your app:

<key>NSAppTransportSecurity</key>
<dict>
  <key>NSExceptionDomains</key>
  <dict>
    <key>yourserver.com</key>
    <dict>
      <!--Include to allow subdomains-->
      <key>NSIncludesSubdomains</key>
      <true/>
      <!--Include to allow HTTP requests-->
      <key>NSTemporaryExceptionAllowsInsecureHTTPLoads</key>
      <true/>
      <!--Include to specify minimum TLS version-->
      <key>NSTemporaryExceptionMinimumTLSVersion</key>
      <string>TLSv1.1</string>
    </dict>
  </dict>
</dict>

Answer 4

I got the same issue on Android 9 because of the "http" and issue resolved by just adding android:usesCleartextTraffic="true" in AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<application
  android:usesCleartextTraffic="true"
 .......>
 .......
</application>

Answer 5

For us it was because we were uploading a file and the RN filePicker did not give the proper mime type. It just gave us 'image' as the type. We needed to change it to 'image/jpg' to get the fetch to work.

form.append(uploadFileName, {
  uri : localImage.full,
  type: 'image/jpeg',
  name: uploadFileName
 })

Answer 6

if you using localhost just change it :

from :http://localhost:3030 to :http://10.0.2.2:3030

Answer 7

I got the same issue on Android but I managed to find a solution for it. Android is blocking cleartext traffic (non-https-requests) since API Level 28 by default. However, react-native adds a network-security-config to the debug version (android/app/src/debug/res/xml/react_native_config.xml) which defines some domains (localhost, and the host IPs for AVD / Genymotion), which can be used without SSL in dev mode. You can add your domain there to allow http requests.

<?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 includeSubdomains="true">dev.local</domain>
  </domain-config>
</network-security-config>

Answer 8

For Android user:

1. Replace localhosts to a Lan IP addresses because when you run the project on an Android device, localhost is pointing to the Android device, instead of your computer, example: change http://localost to http://192.168.1.123

2. If your request URL is HTTPS and your Android device is under a proxy, assume you have installed User-added CA(like burp suite's CA or Charles's CA) in your Android device, make sure your Android version is below Nougat(7.0), because: Changes to Trusted Certificate Authorities in Android Nougat
   

   User-added CAs
   Protection of all application data is a key goal of the Android application sandbox. Android Nougat changes how applications interact with user- and admin-supplied CAs. By default, apps that target API level 24 will—by design—not honor such CAs unless the app explicitly opts in. This safe-by-default setting reduces application attack surface and encourages consistent handling of network and file-based application data.

Answer 9

React Native Docs gives the answer for this.

Apple has blocked implicit cleartext HTTP resource loading. So we need to add the following our project's Info.plist (or equivalent) file.

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSExceptionDomains</key>
    <dict>
        <key>localhost</key>
        <dict>
            <key>NSTemporaryExceptionAllowsInsecureHTTPLoads</key>
            <true/>
        </dict>
    </dict>
</dict>

React Native Docs -> Integration With Existing Apps -> Test your integration -> Add App Transport Security exception

Answer 10

The problem may be in server configuration.

Android 7.0 has a bug described here. Workaround proposed by Vicky Chijwani:

Configure your server to use the elliptic curve prime256v1. For example, in Nginx 1.10 you do this by setting ssl_ecdh_curve prime256v1;

Answer 11

I was having this problem for Android-

URL- localhost/authToken.json - didn't work :(

URL- 10.106.105.103/authToken.json - didn't work :(

URL- http://10.106.105.103/authToken.json - worked :) :D

Note- Use ifconfig on Linux or ipconfig on Windows to find machine IpAddress

Answer 12

I came across the same issue on Android Emulator, where I tried to access an external HTTPS URL with a valid certificate. But fetching that URL in react-native failed

'fetch error:', { [TypeError: Network request failed]
sourceURL: 'http://10.0.2.2:8081/index.delta?platform=android&dev=true&minify=false' }

1) To find out the exact error in the logs, I first enabled 'Debug JS Remotely' using Cmd + M on the app

2) The error reported was

java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.

3) I added the URL's valid certificate using this method -> STEP 2

http://lpains.net/articles/2018/install-root-ca-in-android/

This certificate gets added to the User tab.

4) Add the attribute android:networkSecurityConfig attribute to AndroidManifest.xml

Add a Network Security Configuration file res/xml/network_security_config.xml:

<network-security-config>
    <base-config>
        <trust-anchors>
            <certificates src="user"/>
            <certificates src="system"/>
        </trust-anchors>
    </base-config>
</network-security-config>

This should work and give you an expected response.

Answer 13

For Android, you may have missed to add permission in AndroidManifest.xml Need to add the following permission.

<uses-permission android:name="android.permission.INTERNET" /> 

Answer 14

I have similar problem. In my case requests to localhost was working and suddenly stopped. It turn out that the problem was that I was turn off my wifi on my android phone.

Answer 15

in my case i have https url but fetch return Network Request Failed error so i just stringify the body and it s working fun

fetch('https://mywebsite.com/endpoint/', {
  method: 'POST',
  headers: {
    Accept: 'application/json',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    firstParam: 'yourValue',
    secondParam: 'yourOtherValue'
  })
});

Answer 16

By running the mock-server on 0.0.0.0
Note: This works on Expo when you are running another server using json-server.

Another approach is to run the mock server on 0.0.0.0 instead of localhost or 127.0.0.1.

This makes the mock server accessible on the LAN and because Expo requires the development machine and the mobile running the Expo app to be on the same network the mock server becomes accessible too.

This can be achieved with the following command when using json-server

json-server --host 0.0.0.0 --port 8000 ./db.json --watch

Visit this link for more information.

Answer 17

Just add

<uses-permission android:name="android.permission.INTERNET" />

    <application
      android:usesCleartextTraffic="true"

in your AndroidManifest.xml and then replace fetch URL domain (localhost) with your IP address,

const dataRaw = await fetch('http://192.168.8.102:4000');

Answer 18

This worked for me, android uses a special type of IP address 10.0.2.2 then port number

import { Platform } from 'react-native';

export const baseUrl = Platform.OS === 'android' ?
    'http://10.0.2.2:3000/'
: 
'http://localhost:3000/';

Answer 19

if you use docker for the REST api, a working case for me was to replace hostname: http://demo.test/api with the machine ip address: http://x.x.x.x/api . You can get the IP from checking what ipv4 you have on your wireless network. You should have also the wifi from phone on.

Answer 20

You should handle the error case in .then for fetch API.

For example:

fetch(authURl,{ method: 'GET'})
.then((response) => {      
  const statusCode = response.status;
  console.warn('status Code',statusCode);
  if(statusCode==200){
    //success code
  }else{
    //handle other error code
  }      
},(err) => {
  console.warn('error',err)
})
.catch((error) => {
  console.error(error);
  return error;
});

Answer 21

For me ... I have https already ... and the issue went away once I added 'Content-type': 'application/json' to headers

headers: {
  Authorization: token,
  'Content-type': 'application/json',
  /** rest of headers... */
}

Platform: Android

Answer 22

This is not an answer but option. I switched to https://github.com/joltup/rn-fetch-blob It works good both for form-data and files

Answer 23

HTTP is not allowed anymore. Pleas use HTTPS

Starting with Android API 28 and iOS 9, these platforms disable insecure HTTP connections by default.

Answer 24

It my case, it was showing same for https requests as well.

Reinstalling the application solved it.

Answer 25

Had the same issue with React-native Expo and Node Express back-end. The problem is about a conflict between an emulator localhost and server localhost. Your back-end-server might be ruunning on 127.0.0.1:8000, but an emulator can't find this.

In terminal find your Ipv4-Address with a command 'ipconfig'. For ex., it will be 192.138.1.40

After this put it into your fetch ( 'http://192.138.1.40:8080/'). And what is also important - run your back-end-server with the same host and port. On Node Express for example:

app.listen(8080, () => console.log("Server is running!"))

Answer 26

In my case i just change https to http and the problem was resolved (Using android studio).

Answer 27

The solution is simple update nodejs version 14 or higher

Answer 28

"dependencies": {"react": "17.0.2","react-native": "0.66.1"}, I faced this problem with the Android emulator.

1. Add these lines of code inside AndroidManifest.xml

    <application
     ....
     ....
    android:usesCleartextTraffic="true">
   

2. Then, try to run your code in a real physical device, instead of emulator,
   to run on physical devices - connect your usb and try to run npx react-native run-android

Answer 29

fixed TypeError: Network request failed when upload file to http not https with Android debug builds

In react-native 0.63.2 (I'm testing) or some higher version, if just use fetch to upload file to a http (not https) server, will meet TypeError: Network request failed.

Here I use axios@0.27.2 as client running on an Android phone successfully upload a file to react-native-file-server as server running on another Android phone.

client need edit JAVA and JS code, server no need edit JAVA code.

With debug builds, must commenting out line number 43 in this file android/app/src/debug/java/com/YOUR_PACKAGE_NAME/ReactNativeFlipper.java

38      NetworkFlipperPlugin networkFlipperPlugin = new NetworkFlipperPlugin();
39      NetworkingModule.setCustomClientBuilder(
40          new NetworkingModule.CustomClientBuilder() {
41            @Override
42            public void apply(OkHttpClient.Builder builder) {
43      //        builder.addNetworkInterceptor(new FlipperOkhttpInterceptor(networkFlipperPlugin));
44            }
45          });
46      client.addPlugin(networkFlipperPlugin);

Maybe also need add android:usesCleartextTraffic="true" under <application of android/app/src/main/AndroidManifest.xml , on my test, it's not necessary on both debug and release builds.

  onFileSelected = async (file) => {
    // API ref to the server side BE code `addWebServerFilter("/api/uploadtodir", new WebServerFilter()`
    // https://github.com/flyskywhy/react-native-file-server/blob/1034a33dd6d8b0999705927ad78368ca1a639add/android/src/main/java/webserver/WebServer.java#L356
    // could not be 'localhost' but IP address
    const serverUploadApi = 'http://192.168.1.123:8080/api/uploadtodir';

    // the folder on server where file will be uploaded to, could be e.g. '/storage/emulated/0/Download'
    const serverFolder = '/storage/emulated/0/FileServerUpload';

    const fileToUpload = {
      // if want to upload and rename, it can be `name: 'foo.bar'`, but can not be 'foo'
      // only if your server upload code support file name without type, on our server
      // https://github.com/flyskywhy/react-native-file-server/blob/1034a33dd6d8b0999705927ad78368ca1a639add/android/src/main/java/webserver/WebServer.java#L372
      // will cause java.lang.StringIndexOutOfBoundsException in substring()
      name: file.name,

      // type is necessary in Android, it can be 'image/jpeg' or 'foo/bar', but can not be
      // 'foo', 'foo/', '/foo' or undefined, otherwise will cause `[AxiosError: Network Error]`
      type: 'a/b',

      uri: Platform.OS === 'android' ? file.uri : file.uri.replace('file://', ''),
    };

    const form = new FormData();
    form.append('path', serverFolder);
    form.append('uploadfile', fileToUpload);

    // ref to the server side FE code `this.axios.post("/api/uploadtodir", parms, config)`
    // https://github.com/flyskywhy/react-native-file-server/blob/1034a33dd6d8b0999705927ad78368ca1a639add/fileserverwebdoc/src/views/Manage.vue#L411
    let res = await axios.post(serverUploadApi, form, {
      headers: {
        'Content-Type': 'multipart/form-data',
      },
      onUploadProgress: function (progressEvent) {
        console.warn(progressEvent);
      },
    });

    // ref to the server side BE code `return newFixedLengthResponse("Suss");`
    // https://github.com/flyskywhy/react-native-file-server/blob/1034a33dd6d8b0999705927ad78368ca1a639add/android/src/main/java/webserver/WebServer.java#L380
    if (res.data === 'Suss') {
      console.warn('Upload Successful');
    } else if (res.data === 'fail') {
      console.warn('Upload Failed');
    }
  };

Answer 30

If you are connecting to a HTTPS website please check the internet connection of your emulator. (In my case, I'm using a connected phone emulator via USB and it's internet was offline)