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

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 3

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 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

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 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

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 9

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 10

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 11

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 12

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 13

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 14

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 15

if you using localhost just change it :

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

Answer 16

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 17

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 18

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 19

1. Add android:usesCleartextTraffic="true" line in AndroidManifest.xml.

2. Delete all debug folder from your android folder.

Answer 20

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 21

The solution is simple update nodejs version 14 or higher

Answer 22

In my case, the Android emulator wasn't connected to the Wi-Fi.

See here Android Studio - Android Emulator Wifi Connected with No Internet

Answer 23

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 24

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 25

Just you have Changes in Fetch....

fetch('http://facebook.github.io/react-native/movies.json')
    .then((response) => response.json())
    .then((responseJson) => {
        /*return responseJson.movies; */
        alert("result:"+JSON.stringify(responseJson))
        this.setState({
            dataSource:this.state.dataSource.cloneWithRows(responseJson)
        })
     }).catch((error) => {
         console.error(error);
     });

Answer 26

For Android devices, go to your project root folder and run the command:

adb reverse tcp:[your_own_server_port] tcp:[your_own_server_port]

e.g., adb reverse tcp:8088 tcp:8088

This will make your physical device(i.e. Android phone) listen to the localhost server running on your development machine (i.e. your computer) on address http://localhost:[your_own_server_port].

After that, you can directly use http:localhost:[your_port] /your_api in your react-native fetch() call.

Answer 27

For android, add android:networkSecurityConfig="@xml/network_security_config" to application tag in AndroidManifest.xml, like this:

    <?xml version="1.0" encoding="utf-8"?>
    <manifest ... >
        <application android:networkSecurityConfig="@xml/network_security_config"
                        ... >
            ...
        </application>
    </manifest>

network_security_config.xml file content:

<?xml version='1.0' encoding='utf-8'?>
<network-security-config>
<debug-overrides>
    <trust-anchors>
        <!-- Trust user added CAs while debuggable only -->
        <certificates src="user" />
    </trust-anchors>
</debug-overrides>

<!-- let application to use http request -->
<base-config cleartextTrafficPermitted="true" />
</network-security-config>