Fix Claude Mobile App Connection Error on iOS & Android

Troubleshooting Claude Mobile App Network Issues

Unlike web browsers, mobile applications rely on rigid API integrations. When Anthropic experiences high traffic loads, minor server degradation, or rolling backend updates, the mobile app can lose connection, fail to authenticate, or hang on a black screen. This behavior occurs because the app's internal timeout thresholds are often less resilient than a standard web browser.

Before assuming your internet connection is entirely at fault, use this guide to identify and resolve mobile-specific routing and app-state issues.

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Step-by-Step Fixes for Mobile Connection Failures

1. Force Close and Purge App RAM Simply exiting to your home screen does not close the Claude app; it remains suspended in your phone’s temporary memory (RAM), preserving the broken connection state.

• iOS (iPhone/iPad): Swipe up from the bottom of the screen (or double-click the Home button), locate the Claude preview card, and swipe it up and off the screen.
• Android: Swipe up to access your recent apps overview, find Claude, and swipe it away. Alternatively, go to Settings > Apps > Claude and tap Force Stop.

Reopen the app to initiate a completely fresh handshake with the server.

2. Isolate Cellular vs. Wi-Fi Routing Your mobile carrier’s gateway may be experiencing packet loss to Anthropic's hosting provider (such as AWS), or your local Wi-Fi router might be blocking the WebSocket connections Claude uses to stream responses.

1. Turn off Wi-Fi in your phone's settings to force a cellular connection. Attempt to send a message in Claude.
2. If that fails, toggle cellular off, connect to a high-speed Wi-Fi network, and test again.
3. If both fail, toggle Airplane Mode on for 15 seconds to reset your device's radio transceivers, then turn it off and retry.

3. Clear the Claude App Cache (Android Only) On Android devices, corrupted temporary app files can prevent the app from authenticating your session.

1. Open your device's Settings app.
2. Go to Apps or Application Manager.
3. Tap Claude from the list.
4. Select Storage or Storage & cache.
5. Tap Clear cache. (Do not select "Clear storage" unless you are prepared to log in again, as this removes local login tokens).

4. Check for App Updates and OS Compatibility Outdated versions of the Claude app may use deprecated API endpoints that Anthropic has disabled during server maintenance or security upgrades.

• iOS: Open the App Store, search for "Claude," and tap Update if a new version is available.
• Android: Open the Google Play Store, tap your profile icon, select Manage apps & device, find Claude under "Updates available," and tap Update.

5. Disable Private DNS or Custom Adblock VPNs Mobile security apps (like AdGuard, NordVPN, or customized Private DNS settings) often inspect and block secure WebSocket connections (`wss://` protocols) that Claude uses to stream text generation.

1. Temporarily disable any active VPN profile in your phone's settings.
2. On Android, go to Settings > Network & Internet > Private DNS and set it to Automatic or Off.
3. On iOS, go to Settings > General > VPN & Device Management and ensure no profiles are actively intercepting your traffic.

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When to Escalate

If you have updated the app, switched network types, cleared cache, and disabled security software, but still receive a "Connection Error" message, check if you can log in to Claude via a mobile web browser (like Safari or Chrome) on the exact same device.

If the web version works but the app does not, the issue is an active bug within the app package or a localized mobile API endpoint outage. Report this to Anthropic directly through the in-app settings (tap your profile icon, select Support, and file a bug report) or email support@anthropic.com with your phone's exact model, OS version, and app version number.