If your monitor shows a "Blocked" status (displayed in blue/teal), it means the website is behind a Web Application Firewall (WAF) or bot protection service that is preventing our monitoring checks from accessing the page.
What Does "Blocked" Mean?
A "Blocked" status means:
- The server IS responding — your website's infrastructure is online and working
- The WAF is doing its job — it's correctly identifying and blocking automated requests
- Real visitors are NOT affected — browsers pass WAF challenges automatically
- We cannot fully verify the page content — so we show "Blocked" rather than "Up" to be transparent
Why Does This Happen?
Services like Cloudflare, Sucuri, Akamai, and AWS WAF use several techniques to detect automated traffic:
- TLS Fingerprinting (JA3/JA4) — identifies the HTTP client based on how it establishes SSL connections. Server-side monitoring tools have different fingerprints than real browsers.
- JavaScript Challenges — "Checking your browser..." pages that require JavaScript execution to proceed
- CAPTCHA Challenges — visual puzzles that require human interaction
- Behavioral Analysis — detecting request patterns that don't match normal browsing
Even though WebMon sends browser-like headers, advanced WAFs look beyond HTTP headers to detect automated requests.
Is "Blocked" a Problem?
Usually not. If your monitor shows "Blocked", it typically means:
| Scenario | What It Means |
|---|---|
| Your site has Cloudflare with "Under Attack" mode | WAF is actively challenging all visitors — your site is protected |
| Your site has bot protection enabled | Working as intended — automated requests are blocked |
| The site occasionally shows "Blocked" | WAF rules may vary based on traffic patterns or threat levels |
Key Differences from Other Statuses
| Status | Meaning | Alert? |
|---|---|---|
| Up | Site is online and responding normally | No |
| Blocked | Server is responding but WAF blocked our check | No |
| Down | Site is unreachable or returning errors | Yes |
| Unknown | No check has been performed yet | No |
Important: "Blocked" will not trigger any alerts or notifications. It is an informational status only.
What Can I Do About It?
If you want your monitor to show "Up" instead of "Blocked", you can:
- Whitelist our monitoring IP in your WAF/Cloudflare settings (contact us for our IP addresses)
- Create a WAF exception rule for our User-Agent or a specific URL path used for health checks
- Use a dedicated health check endpoint — create a simple page (e.g.
/health) that your WAF is configured to allow through, and monitor that URL instead
Which Services Trigger "Blocked"?
WebMon detects WAF responses from these providers:
- Cloudflare — the most common, including "Under Attack" and "Bot Fight" modes
- Sucuri — website firewall and DDoS protection
- Akamai — enterprise CDN and security
- AWS WAF — Amazon Web Services firewall
- Other services that display challenge pages (detected by page content patterns)
If you believe your monitor is incorrectly showing "Blocked", please contact us and we'll investigate.