Website Uptime Monitor
Monitor website availability and server information for any domain
21health.cn
Uptime & Server Information
Current Status
Historical Data
| Date | Status | Server |
|---|---|---|
| 8/10/2026, 10:57:10 AM | Active | nginx |
| 8/7/2026, 1:44:10 PM | Inactive | Unknown |
| 7/19/2026, 3:29:56 AM | Active | nginx |
| 6/30/2026, 3:44:50 AM | Active | nginx |
| 6/22/2026, 2:36:40 AM | Active | nginx |
| 6/10/2026, 10:59:57 PM | Active | nginx |
| 5/22/2026, 11:48:43 AM | Active | nginx |
| 4/23/2026, 5:35:31 PM | Active | nginx |
| 4/16/2026, 9:25:48 AM | Active | nginx |
| 1/20/2026, 6:20:01 AM | Active | nginx |
| 1/18/2026, 7:10:24 AM | Inactive | Unknown |
| 1/15/2026, 7:18:23 AM | Active | nginx |
| 11/11/2025, 3:33:56 PM | Inactive | Unknown |
| 11/8/2025, 8:33:06 PM | Inactive | Unknown |
| 9/7/2025, 7:01:00 PM | Active | nginx |
| 8/12/2025, 11:37:03 PM | Inactive | Unknown |
Don't just check uptime once — watch it 24/7
This is a one-time check. Turn on monitoring and we'll watch the domains that matter to you continuously, notifying you the moment anything moves across all three signals:
Uptime
We visit the site from multiple regions worldwide and email you within minutes if it goes down, with a per-region breakdown so a real outage stands out from a regional blip.
DNS changes
We watch NS, MX, CAA, DNSSEC, CNAME and A/AAAA records, and identify the host, network, and ASN behind them, so a real migration or hijack stands out from routine noise.
TLS certificate
We warn you 30, 14, 7, and 1 days before it expires, and flag it if the issuing authority changes or the certificate is unexpectedly replaced.
Free for your first domain: uptime, DNS, and certificate together. No credit card.
About Website Uptime Monitoring
Use the Who.is uptime information to track the availability and server information of websites. This helps track:
- Website availability and response status
- Server software and configuration
- Meta information including titles and descriptions
- Historical uptime patterns
This information is valuable for website owners, system administrators, and anyone interested in monitoring website reliability and performance.
Metrics we monitor
- Uptime percentage: The percentage of time your website is accessible
- Response time: How quickly your server responds to requests
- Status codes: HTTP response codes indicating server status
Disclaimer: Who.is is not affiliated with, endorsed by, or connected to any of the domains displayed on this page. We provide this information as a public service for informational purposes only.