Fix Claude Stuck on Cloudflare Checking Browser

When trying to access Claude, you may encounter an infinite loop where the page continuously displays "Checking your browser before accessing claude.ai" or repeatedly asks you to solve a CAPTCHA. This occurs because Cloudflare (Anthropic's security provider) is flagging your connection pattern, browser fingerprint, or IP address as potential bot behavior.

To pass this security check and access the web interface, you must resolve the discrepancies in your browser profile that are triggering Cloudflare's security shields.

Step 1: Disable Ad Blockers and Privacy Extensions Aggressive ad blockers, script blockers, and privacy-focused extensions can block the background JavaScript files Cloudflare uses to verify your browser's legitimacy. 1. Open your browser's extension manager (e.g., `chrome://extensions` in Chrome). 2. Temporarily toggle off extensions like uBlock Origin, Privacy Badger, NoScript, or Ghostery. 3. Reload the Claude web page and complete the verification step. 4. If this resolves the loop, whitelist `claude.ai` and `anthropic.com` within those extensions rather than keeping them permanently disabled.

Step 2: Synchronize Your System Clock Cloudflare uses time-sensitive cryptographic tokens to grant browser clearance. If your computer's system time differs from the actual internet time by even a few seconds, the security check will fail silently and loop continuously. 1. **On Windows:** Go to **Settings** > **Time & Language** > **Date & Time**. Ensure "Set time automatically" is toggled on, and click **Sync now** under the synchronizing clock section. 2. **On macOS:** Go to **System Settings** > **General** > **Date & Time**. Toggle on "Set time and date automatically" and verify your correct time zone. 3. Refresh Claude and try again.

Step 3: Turn Off Fingerprint Protection (Brave/Firefox) If you are using browsers focused on privacy, built-in fingerprint blocking features can prevent Cloudflare from executing its browser verification scripts. 1. **In Brave:** Click the orange Brave Shields icon in the URL bar while on Claude. Toggle the shields off for this site, or change the setting for "Block fingerprinting" to standard/disabled. 2. **In Firefox:** Go to **Settings** > **Privacy & Security**. If your Enhanced Tracking Protection is set to "Strict", change it to "Standard" and reload the page.

Step 4: Clear Cloudflare Specific Cookies Sometimes your browser stores a corrupted or expired Cloudflare clearance token, causing the security firewall to reject your requests repeatedly. 1. In your browser settings, search for **Cookies and other site data**. 2. Search specifically for `cf_clearance` or `__cf_bm` cookies under the `claude.ai` domain. 3. Delete these specific cookies. 4. Reload the page to force Cloudflare to issue a fresh, valid security token.

Step 5: Switch to a Different Internet Network Your current public or shared IP address might have been flagged for suspicious activity, causing Cloudflare to apply a blanket block. 1. If you are on a public Wi-Fi network, temporarily switch to a mobile hotspot. 2. If you are using a VPN, change your server location or disconnect entirely to get a clean, residential IP address.

When to escalate If you have adjusted your browser settings, synchronized your clock, and tried different networks but remain locked out by Cloudflare, your IP range may be globally blocked. You will need to contact Anthropic Support via their main help center. Provide them with your IP address and the Ray ID displayed at the bottom of the Cloudflare challenge page so they can manually inspect your access block.