If WebCheck reports a Cloudflare challenge, your website may still be working normally for visitors. Cloudflare challenged the monitoring request instead of allowing WebCheck to reach the page.
Why does Chrome work when WebCheck is challenged?
Chrome can run Cloudflare browser verification and retain clearance cookies. WebCheck uses a secure, bounded server-side request and does not attempt to solve browser challenges.
What should I check?
Review Cloudflare Security Events for the request. Bot Fight Mode, Super Bot Fight Mode, Under Attack Mode, WAF managed challenges and rate limiting can all affect server-side monitoring.
- Prefer a dedicated public health endpoint where appropriate.
- Allow only the monitoring service or endpoint rather than disabling protection globally.
- Do not weaken TLS or network safety controls to make a check pass.
A challenge is different from downtime
A normal Cloudflare HTTP 200 is healthy. A 403 response with cf-mitigated: challenge is reported as an edge warning. Ordinary 5xx responses, timeouts and connection failures remain possible outages.
An application maintenance page returning HTTP 503 is service unavailability and should be investigated as maintenance or application downtime.