How to Fix Claude Stuck on Loading Screen & Blank Pages

When the Claude web application fails to progress past the initial loading animation, or displays a blank screen indefinitely, it indicates a failure to initialize the frontend interface. This occurs when your browser cannot download, unpack, or execute the JavaScript bundles required to run the application.

This guide covers the most common causes of this issue—including CDN caching errors, blocked secure WebSockets, and local storage corruption—and how to resolve them.

1. Clear local IndexedDB and application state Claude uses your browser’s IndexedDB and LocalStorage to cache system files and chat session indexes. If these local databases become corrupted, the web app's startup scripts will stall, leaving you stuck on the loading screen. 1. In Google Chrome or Microsoft Edge, press `F12` (or `Cmd` + `Option` + `I` on Mac) to open Developer Tools. 2. Click on the **Application** tab at the top of the panel (you may need to click the `>>` icon to see it). 3. In the left sidebar, expand **Storage**. 4. Click on **Clear site data**. 5. Ensure all boxes (including IndexedDB, Local storage, and Cookies) are checked, then click **Clear site data**. 6. Refresh the page.

2. Check for Cloudflare and CDN blocks Anthropic uses Cloudflare to protect its infrastructure from DDoS attacks and to distribute its web assets globally. If your IP address has been flagged, or if the CDN node nearest to you is experiencing a localized routing failure, the script assets will fail to download. 1. Open your browser console by pressing `F12` and selecting the **Console** tab. 2. Look for red error messages indicating failed network resources (e.g., `Failed to load resource: net::ERR_CONNECTION_REFUSED` or `403 Forbidden`). 3. If you see connection block errors, temporarily disable your VPN, proxy, or custom DNS service (such as NextDNS or Pi-hole) that might be blocking Anthropic's content delivery subdomains. 4. Try loading the page using your mobile device’s cellular data connection. If it works, your home or office router network is blocking the CDN.

3. Verify WebSocket (WSS) connectivity Unlike standard websites that load static HTML, Claude uses secure WebSockets (`wss://`) to establish a continuous, real-time connection for streaming messages. If your network, firewall, or security software blocks WebSocket handshakes, the application UI will freeze during its loading phase. 1. Go to `websocketstest.com` or a similar diagnostic tool to verify that your browser and internet connection support WebSockets. 2. If WebSockets are blocked, check your local antivirus software (such as Kaspersky, Avast, or Bitdefender). Many of these suites have "Web Shield" or HTTPS scanning features that intercept and block WebSocket connections. Temporarily disable HTTPS scanning to test. 3. If you are on a corporate network, contact your IT administrator to ensure ports `80`, `443`, and `8080` are open for WebSocket traffic to `*.anthropic.com` and `*.claude.ai`.

4. Disable conflicting extensions and ad blockers Ad-blocking extensions and privacy shields often flag tracking scripts or WebSocket endpoints, occasionally blocking essential application scripts by mistake. 1. If you use Brave Browser, click the lion icon in the address bar and toggle **Shields** off for Claude. 2. If you use Chrome, Firefox, or Safari, temporarily disable ad-blocking extensions like uBlock Origin, AdGuard, or Privacy Badger. 3. Disable any custom CSS/JS injectors (like Tampermonkey or Stylus) that run scripts on `claude.ai`. 4. Reload the page.

How partial outages cause UI freezes Sometimes, Claude experiences a partial outage where the core servers are running, but the frontend deployment server is down. In this scenario, your browser successfully reaches the URL, but the static files needed to build the UI fail to download, resulting in a permanent loading wheel. Always cross-reference your experience with `status.anthropic.com` to see if a "Frontend UI Deployment" incident has been reported.

When to escalate If Claude remains stuck on the loading screen across multiple distinct devices (such as both your phone and laptop) on different networks, and no outage is listed on the Anthropic status page, there may be an issue with your specific user account profile. Contact Anthropic Support by sending an email directly to `support@anthropic.com` since you cannot access the in-app help widget. Detail the troubleshooting steps you have already attempted.