Fix Claude Web App Stuck on Pulsing Logo

When attempting to access claude.ai, users sometimes encounter a loop where the main interface fails to compile, leaving only the central orange Claude icon pulsing on a white or dark background. This typically occurs because of an interrupted asset delivery pipeline, a corrupted service worker cached in your browser, or a localized Content Delivery Network (CDN) routing failure during minor service disruptions.

To break out of this loading loop and force the web application to fetch a working, uncorrupted session, follow these troubleshooting steps.

1. Perform a Hard Refresh

A standard refresh (pressing F5 or clicking the reload button) often loads the page using stored local assets, preserving the corruption. A hard refresh forces the browser to discard its local files and download everything fresh from Anthropic's active web servers.

• Windows (Chrome, Edge, Firefox): Press Ctrl + F5, or hold down Ctrl and click the reload icon.
• Mac (Chrome, Firefox): Press Cmd + Shift + R.
• Mac (Safari): Hold Shift and click the Reload button in the address bar.

2. Clear Claude Site Data and Cache

If the hard refresh fails, persistent storage (such as IndexedDB state, local storage, or service workers) may be preventing the app from initializing.

For Google Chrome & Chromium-based browsers: 1. Navigate to **claude.ai**. 2. Click the padlock icon or tuning icon to the left of the URL in the address bar. 3. Click **Site settings**. 4. Under the Usage section, click **Clear data**. 5. Restart your browser, go back to claude.ai, and sign back in.

For Mozilla Firefox: 1. Click the padlock icon next to the URL. 2. Click **Clear cookies and site data...** 3. Confirm by clicking **Remove**. 4. Reload the page.

3. Deregister Glitched Service Workers

Claude utilizes service workers to run offline tasks and optimize asset load speeds. If a service worker is stuck in an invalid state, it will permanently block the application loop.

1. With the pulsing logo page open, press F12 (or Cmd + Option + I on Mac) to open Developer Tools.
2. Click on the Application tab (or Storage tab in Firefox).
3. In the left-hand sidebar, select Service Workers under the Application section.
4. Find the service worker associated with claude.ai.
5. Click Unregister on the right side.
6. Reload the page to force the application to download and install a fresh service worker package.

4. Temporarily Disable Extensions

Certain security-focused, ad-blocking, or cookie-management browser extensions can block the background API endpoints Claude needs to verify your authorization session. If these scripts are blocked, the application UI will render but will freeze indefinitely while waiting for credentials.

• Open a new Incognito / Private Window where all third-party extensions are disabled by default.
• Navigate to claude.ai and attempt to log in.
• If the page loads successfully, return to your main window and temporarily disable extensions like uBlock Origin, Privacy Badger, or custom script blockers for the claude.ai domain to isolate the conflicting tool.

5. Switch DNS Resolvers

If Anthropic recently migrated web servers or updated their Cloudflare DNS configurations, your ISP's DNS servers might still be caching outdated routing routes. This disconnect will prevent your client from pulling script updates.

Change your system network settings to use a public, high-availability DNS service: * Google Public DNS: Primary 8.8.8.8, Secondary 8.8.4.4 * Cloudflare DNS: Primary 1.1.1.1, Secondary 1.0.0.1

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When to Escalate

If you have cleared your browser data, tried incognito mode, and tested an alternative network (such as your phone's cellular data hotspot) but the page still hangs on the pulsing logo, the outage is likely on Anthropic's asset delivery network. Check third-party outage aggregation channels or social feeds to confirm if others in your region are experiencing the same issue. If it persists for more than 4 hours, use the support widget on support.anthropic.com to submit a bug report.