Claude Blank Page / White Screen: Fix Cache, Extensions, and Script Blocking

Why Claude Shows a Blank Page

Claude's web interface is a React single-page application (SPA). When you navigate to claude.ai, the browser fetches an HTML shell and then downloads JavaScript bundles that build the actual interface. If any step in this chain fails — a blocked network request, a stale cached file, an extension intercepting scripts, or a WebSocket failure — the HTML shell loads but the app never initializes. The result is a blank or white screen with no error message.

This is distinct from an error page. The browser considers the page loaded, but nothing is running inside it.

Quick Diagnosis: The Two-Minute Test

Before doing anything else, run this test to identify whether the issue is in your browser or on Anthropic's servers:

1. Open a new incognito/private window (Chrome: Ctrl+Shift+N / Mac: Cmd+Shift+N; Firefox: Ctrl+Shift+P; Safari: Cmd+Shift+N)
2. Navigate to claude.ai and sign in
3. Observe whether Claude loads

If Claude loads in incognito: The problem is in your main browser — stale cache, bad session cookie, or an extension. Follow the browser fixes below.

If Claude is still blank in incognito: Switch to a mobile hotspot (completely different network). If Claude works on the hotspot, the issue is your network or ISP. If it is blank everywhere, check status.anthropic.com for an active outage.

Step-by-Step Fix

Step 1 — Clear All Site Data for claude.ai

Stale JavaScript caches are the single most common cause of blank pages. A regular cache clear through the browser menu is often not enough — you need to clear site-specific stored data.

Chrome (most reliable method):

1. Go to chrome://settings/content/all in the address bar
2. Search for claude in the search box
3. Click the trash icon next to each claude.ai entry to delete all stored data
4. Return to claude.ai and sign in fresh

Chrome (quick method from the page):

1. While on claude.ai, click the lock icon in the address bar
2. Click Cookies and site data → Manage on-device site data
3. Select all claude.ai entries and delete them

Firefox:

1. Go to about:preferences#privacy
2. Scroll to Cookies and Site Data → click Manage Data
3. Search for anthropic or claude
4. Select all entries and click Remove Selected
5. Restart Firefox before retesting

Safari:

1. Open Safari → Settings (or Preferences) → Privacy
2. Click Manage Website Data
3. Search for claude → select entries → click Remove
4. Alternatively: Develop menu → Empty Caches (if Develop menu is enabled)

Step 2 — Disable Extensions and Test

Extensions are the second most common cause of blank pages. Disabling them one at a time can pinpoint the culprit, but disabling all at once first confirms whether an extension is responsible.

Chrome:

1. Go to chrome://extensions
2. Toggle off all extensions
3. Reload claude.ai
4. If Claude loads, re-enable extensions one at a time, reloading after each to find the culprit

Firefox:

1. Click the menu → Add-ons and Themes
2. Click the toggle next to each extension to disable
3. Reload claude.ai and test

Extensions most likely to cause blank pages:

• Ad blockers (uBlock Origin, AdBlock Plus, Brave Shields)
• Script blockers (NoScript, uMatrix)
• Privacy tools (Privacy Badger, Ghostery, DuckDuckGo extension)
• VPN browser extensions (ExpressVPN, NordVPN browser extensions)
• Dark mode or page-styling extensions that inject CSS/JS

Step 3 — Browser-Specific Fixes

Each major browser has unique quirks that can cause Claude to blank out.

Chrome-specific:

• Chrome's aggressive cache sometimes ignores site data clears. After clearing, close Chrome completely and reopen it before testing.
• Check chrome://flags — if you have experimental flags enabled (especially around WebSockets or network), reset them to default.
• If you use Chrome profiles, switch to the Default profile or create a new test profile.

Firefox-specific:

• Firefox's Enhanced Tracking Protection (ETP) can block scripts from Anthropic's CDN. Go to the address bar → shield icon → toggle off Enhanced Tracking Protection for claude.ai.
• Firefox containers (from Firefox Multi-Account Containers extension) sometimes isolate sessions incorrectly — remove the container assignment for claude.ai if you use this extension.
• Check about:config for network.websocket.enabled — it must be set to true.

Safari-specific:

• Safari's Intelligent Tracking Prevention (ITP) can delete authentication cookies while you are still using the site. Go to Safari → Settings → Privacy → uncheck "Prevent cross-site tracking" temporarily to test.
• Safari requires a full browser quit (not just window close) for cache clears to take effect — use Cmd+Q after clearing data.
• On iOS Safari: Settings app → Safari → Clear History and Website Data, then reopen.

Step 4 — Disable VPN or Proxy

Claude uses WebSocket connections (wss:// protocol) for streaming responses. Many VPN configurations either:

• Block WebSocket connections entirely
• Route traffic through an exit node with high latency, causing silent timeouts
• Apply SSL inspection that breaks certificate validation

To test:

1. Disable your VPN completely (both the app and any browser extension version)
2. If you use a corporate proxy, test on a mobile hotspot to bypass it entirely
3. Navigate to claude.ai fresh

If Claude loads without the VPN, try switching your VPN server to a different city or country. If your VPN supports protocol switching, try WireGuard instead of OpenVPN (or vice versa) — some protocols handle WebSocket traffic better.

Step 5 — Force a Hard Refresh

A standard page reload (F5 or the refresh button) often serves files from the browser's cache without re-fetching from the server. A hard refresh forces the browser to re-download everything.

• Chrome / Firefox / Edge (Windows/Linux): Ctrl+Shift+R
• Chrome / Firefox / Edge (Mac): Cmd+Shift+R
• Safari (Mac): Cmd+Option+R
• Internet Explorer / Edge Legacy: Ctrl+F5

If the page still loads blank after a hard refresh, the issue is not just a cached HTML file — proceed to the site data clear in Step 1.

Step 6 — Try a Different Browser

If the issue persists after Steps 1-5 in your primary browser, test in a completely different browser application:

• Primary browser is Chrome → test in Firefox or Edge
• Primary browser is Firefox → test in Chrome or Safari
• On mobile → test in the built-in browser (Safari on iOS, Chrome on Android)

If Claude loads in the alternate browser, the issue is specific to your primary browser installation and may require a full browser reinstall in severe cases.

Step 7 — Check status.anthropic.com

Go to status.anthropic.com before spending more time troubleshooting. If Anthropic's services are degraded or experiencing an active incident, no local fix will resolve it — you simply need to wait.

The status page shows real-time status for: API, claude.ai web, Claude.ai for iOS/Android, and Console. Check the Incident History tab if the main status shows "Operational" but you are still having issues — sometimes there is a brief lag between an incident starting and it being posted.

Why This Happens

Stale cached JavaScript bundles: Claude's app updates frequently. Browsers cache JavaScript bundles aggressively. When Anthropic deploys an update, older cached bundles can be incompatible with the current server-side code, causing initialization to fail silently. The fix is always to delete cached site data — not just cookies.

Extension interference: Content Security Policy violations or blocked network requests prevent the React app from mounting. The browser security sandbox stops the app mid-initialization with no visible error message. This is by design — browsers do not surface these failures to users to prevent fingerprinting attacks.

WebSocket blocking: Claude streams responses using WebSocket connections on port 443 with the wss:// protocol. Corporate firewalls, some ISPs, and certain VPN configurations block WebSocket upgrade requests even when they pass through standard HTTPS ports. The app loads the visual shell but fails silently when it tries to establish the streaming connection.

Common Mistakes to Avoid

• Refreshing the same page repeatedly without clearing cache — a normal refresh serves the same broken cached files; use Ctrl+Shift+R or clear site data first
• Skipping the incognito test — this single step immediately tells you whether the issue is in your browser or on Anthropic's servers, saving significant troubleshooting time
• Disabling the system VPN but not the browser VPN extension — a browser VPN extension stays active even when your system-level VPN is off; you must disable both independently
• Clearing only cookies — cookies alone will not fix a stale JavaScript cache; you must explicitly clear cached files and site data as well
• Assuming a site-wide outage without checking — the vast majority of blank page reports are local browser issues, not server outages; always run the incognito test before concluding it is Anthropic's problem
• Not testing on a different network — corporate and home networks can both have filtering rules that only appear when using specific networks

View all Claude guides