How to Fix Claude App Not Working on iPhone or Android

The Claude mobile app (available for iOS and Android) offers a direct, native portal to Claude's models. However, when the app refuses to open, crashes on launch, displays a black screen, or fails to deliver responses with a network connection error, it can be difficult to diagnose whether the cause is a global Anthropic service outage or a localized device error. Mobile operating systems enforce strict sandboxing, background execution, and network routing rules that can easily disrupt Claude's real-time WebSockets.

Follow these structured troubleshooting steps to repair connection and launch issues with the Claude mobile app.

Step 1: Check the Mobile API Gateway and Update the App Anthropic routes mobile app traffic through specific mobile-optimized API gateways that can occasionally experience degraded performance even while the desktop web interface remains fully operational. Furthermore, older versions of the app may be locked out of service due to API schema upgrades. 1. Visit status.anthropic.com on a mobile browser to verify if there is an active outage listed under 'API' or 'Console'. 2. Open the **Apple App Store** (iOS) or **Google Play Store** (Android). 3. Search for 'Claude' and check if an **Update** button is available. If so, tap update immediately. Anthropic frequently releases hotfixes for authentication and API connectivity changes.

Step 2: Switch Network Connections (Carrier NAT vs. Wi-Fi) Mobile networks utilize Carrier-Grade NAT (CGNAT) configurations, which dynamically cycle IP addresses. This IP rotation can break the persistent, stateful WebSocket connections Claude uses to stream responses to your phone. Similarly, public Wi-Fi networks often block the protocols necessary for real-time AI API communication. 1. If you are on Wi-Fi, turn off Wi-Fi in your phone's settings to switch to cellular data. 2. If you are on cellular data, try connecting to a stable home Wi-Fi network. 3. Toggle **Airplane Mode** on for 10 seconds, then turn it off. This forces your mobile device to clear its network routing tables and fetch a new IP address from your carrier.

Step 3: Clear Cache and Force App Stop Corrupted runtime files or an expired authentication token stored in the application directory can cause the Claude app to crash immediately on launch or get stuck on a loading screen. - **Android Devices:** 1. Go to **Settings** > **Apps** (or **App Management**). 2. Select **Claude** from the list. 3. Tap **Force Stop** to terminate all active background processes. 4. Go to **Storage & Cache** and tap **Clear Cache** (do not tap 'Clear Storage' unless you are prepared to log in again). 5. Restart the app. - **iOS Devices:** 1. Swipe up from the bottom of the screen (or double-click the Home button) to open the App Switcher. 2. Swipe up on the Claude preview window to force-close the application. 3. If the app continues to fail, go to **Settings** > **General** > **iPhone Storage** > **Claude**. Tap **Offload App** (this preserves your local data but reinstalls the app binary), then tap **Reinstall App**.

Step 4: Disable Private DNS, Custom VPNs, and iCloud Private Relay Security tools that route your mobile traffic through private relays or filtered DNS servers can block the specific endpoints Claude uses for real-time streaming and telemetry collection. 1. **Disable VPNs:** Open your mobile device's VPN app or system VPN settings and disconnect any active connections. 2. **Turn off iCloud Private Relay (iOS):** Go to **Settings** > **[Your Name]** > **iCloud** > **Private Relay** and toggle it off. 3. **Deactivate Private DNS (Android):** Go to **Settings** > **Network & Internet** > **Private DNS** and set it to **Automatic** or **Off** instead of a custom provider (like AdGuard or NextDNS).

Step 5: Verify Region Compatibility and Account Settings Claude is only available in supported geographical regions. If you travel or use an app store registered to a different country, the app may block connections upon verifying your device's physical location. 1. Ensure your physical location matches a country where Claude is officially supported. 2. Disable any location-spoofing apps or developer-mode mock locations. 3. Verify your phone's system language and region are configured correctly (e.g., matching your billing region).

When to escalate If the Claude app still fails to work after trying these steps, but you can successfully access `claude.ai` via a mobile web browser on the same device, the issue is isolated to the mobile client itself. Contact the mobile development support team by navigating to support.anthropic.com, tapping the message bubble icon, and selecting 'Mobile App Support'. Provide your device model (e.g., iPhone 15 Pro, Pixel 8), OS version, app version number (found in app settings), and your account login email.