Cloudflare's I'm Under Attack Mode performs additional security checks to help mitigate layer 7 DDoS attacks. Validated users access your website and suspicious traffic is blocked. It is designed to be used as one of the last resorts when a zone is under attack (and will temporarily pause access to your site and impact your site analytics).

When enabled, visitors receive an interstitial page.

Enable Under Attack mode

I'm Under Attack Mode is disabled by default for your zone.

For Managed Challenge / I'm Under Attack Mode™, select Custom Pages > View default.

The "Checking your browser before accessing..." challenge determines whether to block or allow a visitor within five seconds. After passing the challenge, the visitor does not observe another challenge until the duration configured in Challenge Passage.

Potential issues

Since the Under Attack mode requires your browser to support JavaScript to display and pass the interstitial page, it is expected to observe impact on third party analytics tools.

Was this helpful?

What did you like?

What went wrong?

Thank you for helping improve Cloudflare's documentation!