Android Error: Cleartext Traffic Not Permitted

The "Cleartext traffic not permitted" error in Android arises when your application attempts to connect to a server using plain, unencrypted HTTP (Hypertext Transfer Protocol) instead of the secure HTTPS (Hypertext Transfer Protocol Secure). Android, particularly from API level 28 (Android 9 Pie) onwards, implements stricter security measures that, by default, disallow cleartext (unencrypted) network traffic for security reasons. This is a crucial step to protect user data from eavesdropping and manipulation.

Why This Error Occurs

The primary reason for this error is to encourage developers to prioritize secure communication channels. Plaintext traffic is vulnerable to man-in-the-middle attacks, where malicious actors can intercept and modify the data being transmitted. By enforcing HTTPS, Android aims to create a more secure ecosystem.

Troubleshooting and Solutions

Here's how you can address this error:

1. Migrate to HTTPS

This is the most recommended and secure approach. Ensure your backend server supports HTTPS and that you have a valid SSL/TLS certificate. Update your application code to use HTTPS URLs instead of HTTP URLs when making network requests. This involves changing URLs like `http://example.com/api` to `https://example.com/api`.

2. Network Security Configuration (For Development/Testing - Use with Caution)

If migrating to HTTPS isn't immediately feasible (for testing or legacy server issues), you can temporarily allow cleartext traffic by modifying your application's network security configuration file. This file is typically located in `res/xml/network_security_config.xml`. If the file doesn't exist, create it. Add the following configuration:

<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">yourdomain.com</domain>
    </domain-config>
</network-security-config>

Replace `yourdomain.com` with the specific domain you need to allow cleartext traffic for. Remember to set `android:networkSecurityConfig="@xml/network_security_config"` in your `AndroidManifest.xml` file within the `application` tag:

<application
    android:name=".MyApplication"
    android:networkSecurityConfig="@xml/network_security_config"
    ...>

Warning: Allowing cleartext traffic weakens security. Only use this approach for development, testing, or when dealing with legacy servers where HTTPS migration is impossible. **Never ship a production app with cleartext traffic permitted if it can be avoided.** Consider using different configurations for debug and release builds.

3. Allow Cleartext Traffic for All Domains (Not Recommended)

You can also permit cleartext traffic for all domains, but this is strongly discouraged due to security risks. You can achieve this by using a broader network security configuration:

<network-security-config>
    <base-config cleartextTrafficPermitted="true" />
</network-security-config>

Again, this significantly reduces your application's security and should only be considered as a last resort in specific, controlled environments.

Best Practices

• Prioritize HTTPS: Always use HTTPS whenever possible.
• Use Network Security Configuration Wisely: If you must use cleartext traffic, scope it down to specific domains and only for development/testing purposes.
• Regularly Review Security: Periodically review your application's security configurations to ensure they are up-to-date and address any new vulnerabilities.

By addressing the "Cleartext traffic not permitted" error responsibly, you can ensure your Android application communicates securely and protects user data.