Website Uptime Monitor
Monitor website availability and server information for any domain
21cen.cn
Uptime & Server Information
Current Status
Historical Data
| Date | Status | Server |
|---|---|---|
| 9/8/2026, 2:16:52 AM | Active | Unknown |
| 8/31/2026, 10:49:33 AM | Active | Unknown |
| 8/23/2026, 11:41:17 AM | Active | Unknown |
| 8/17/2026, 5:25:12 PM | Active | Unknown |
| 5/30/2026, 12:51:52 AM | Inactive | Unknown |
| 5/20/2026, 5:49:49 AM | Inactive | Unknown |
| 5/17/2026, 5:54:30 AM | Inactive | Unknown |
| 5/14/2026, 2:36:06 AM | Inactive | Unknown |
| 5/1/2026, 3:12:14 PM | Inactive | Unknown |
| 4/27/2026, 5:46:16 AM | Inactive | Unknown |
| 4/23/2026, 1:18:34 PM | Inactive | Unknown |
| 4/17/2026, 2:54:19 AM | Inactive | Unknown |
| 2/28/2026, 11:15:36 AM | Inactive | Unknown |
| 2/21/2026, 5:18:19 AM | Inactive | Unknown |
| 2/15/2026, 5:33:08 AM | Inactive | Unknown |
| 2/12/2026, 3:13:40 AM | Inactive | Unknown |
| 2/2/2026, 11:34:31 PM | Inactive | Unknown |
| 1/19/2026, 4:44:41 AM | Inactive | Unknown |
| 1/17/2026, 2:14:16 PM | Inactive | Unknown |
| 1/12/2026, 8:53:12 AM | Inactive | Unknown |
| 12/28/2025, 12:48:41 AM | Inactive | Unknown |
| 12/14/2025, 6:15:36 AM | Inactive | Unknown |
| 12/3/2025, 1:25:48 PM | Inactive | Unknown |
| 12/2/2025, 8:03:13 AM | Inactive | Unknown |
| 11/8/2025, 7:54:39 AM | Inactive | Unknown |
| 11/4/2025, 7:05:35 PM | Inactive | Unknown |
| 11/3/2025, 5:38:53 PM | Inactive | Unknown |
| 11/1/2025, 6:51:18 PM | Inactive | Unknown |
| 10/27/2025, 12:53:36 PM | Inactive | Unknown |
| 10/12/2025, 2:41:38 AM | Active | Unknown |
| 8/26/2025, 8:00:14 PM | Active | Unknown |
| 6/30/2025, 3:11:42 PM | Active | Unknown |
| 6/26/2025, 2:36:49 PM | Active | Unknown |
| 6/24/2025, 10:35:01 PM | Active | Unknown |
| 6/23/2025, 7:45:34 PM | Active | Unknown |
| 6/21/2025, 12:33:58 AM | Inactive | Unknown |
| 6/6/2025, 9:36:40 PM | Active | Unknown |
| 6/1/2025, 6:06:29 PM | Active | Unknown |
| 5/18/2025, 3:22:16 PM | Active | Unknown |
| 5/9/2025, 7:19:59 AM | Active | Unknown |
| 4/13/2025, 2:45:45 AM | Active | Unknown |
| 4/2/2025, 4:03:03 AM | Active | Unknown |
| 3/10/2025, 12:59:58 AM | Active | 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.