Website Down Checker
See whether a site was up at our last check and when it last went down.
columbia.edu
Uptime & Server Information
Current Status
Observed Changes
| Date | Status | Server |
|---|---|---|
| 8/29/2026, 10:05:11 AM | Active | cloudflare |
| 8/6/2026, 6:59:37 PM | Active | cloudflare |
| 7/15/2026, 2:56:27 AM | Active | cloudflare |
| 7/2/2026, 12:12:54 PM | Active | cloudflare |
| 6/12/2026, 11:52:58 AM | Active | cloudflare |
| 5/11/2026, 5:07:04 PM | Active | cloudflare |
| 5/2/2026, 7:33:12 PM | Active | cloudflare |
| 4/26/2026, 8:23:59 AM | Active | cloudflare |
| 3/30/2026, 12:29:53 PM | Inactive | Unknown |
| 3/26/2026, 8:51:17 AM | Active | cloudflare |
| 3/20/2026, 5:07:58 AM | Active | cloudflare |
| 3/2/2026, 2:55:38 PM | Active | cloudflare |
| 2/27/2026, 3:57:34 PM | Active | cloudflare |
| 2/20/2026, 8:57:04 PM | Active | cloudflare |
| 2/11/2026, 7:10:18 PM | Inactive | Unknown |
| 2/6/2026, 12:54:59 AM | Inactive | Unknown |
| 2/1/2026, 10:41:30 AM | Inactive | Unknown |
| 1/28/2026, 1:59:19 PM | Inactive | Unknown |
| 1/24/2026, 12:52:28 PM | Inactive | Unknown |
| 1/22/2026, 8:18:26 AM | Inactive | Unknown |
| 1/20/2026, 7:14:56 PM | Inactive | Unknown |
| 1/19/2026, 12:40:00 PM | Inactive | Unknown |
| 1/18/2026, 1:25:37 AM | Inactive | Unknown |
| 1/17/2026, 12:48:16 AM | Inactive | Unknown |
| 1/13/2026, 9:51:35 PM | Inactive | Unknown |
| 1/12/2026, 1:22:26 PM | Active | cloudflare |
| 1/10/2026, 4:43:51 PM | Inactive | Unknown |
| 1/8/2026, 3:32:36 AM | Active | cloudflare |
| 1/5/2026, 2:59:00 AM | Inactive | Unknown |
| 1/2/2026, 9:24:35 AM | Inactive | Unknown |
| 12/31/2025, 2:23:26 AM | Inactive | Unknown |
| 12/25/2025, 9:26:04 AM | Inactive | Unknown |
| 12/23/2025, 8:37:18 AM | Inactive | Unknown |
| 12/21/2025, 11:58:28 AM | Inactive | Unknown |
| 12/19/2025, 6:41:37 PM | Inactive | Unknown |
| 12/18/2025, 5:05:01 PM | Inactive | Unknown |
| 12/16/2025, 9:04:59 PM | Active | cloudflare |
| 12/15/2025, 8:40:34 AM | Active | cloudflare |
| 12/13/2025, 8:27:30 PM | Active | cloudflare |
| 12/12/2025, 3:30:44 PM | Active | cloudflare |
| 12/11/2025, 6:57:53 AM | Inactive | Unknown |
| 12/9/2025, 9:30:41 AM | Active | cloudflare |
| 12/8/2025, 2:01:51 AM | Active | cloudflare |
| 12/6/2025, 11:30:28 PM | Active | cloudflare |
| 12/1/2025, 9:50:52 PM | Active | cloudflare |
| 11/30/2025, 11:44:30 AM | Active | cloudflare |
| 11/25/2025, 12:46:59 AM | Active | cloudflare |
| 11/23/2025, 10:27:42 PM | Active | cloudflare |
| 11/21/2025, 4:08:17 PM | Active | cloudflare |
| 11/19/2025, 9:26:10 AM | Active | cloudflare |
| 11/17/2025, 8:59:09 AM | Active | cloudflare |
| 11/15/2025, 8:16:55 PM | Active | cloudflare |
| 11/12/2025, 7:25:15 PM | Active | cloudflare |
| 11/11/2025, 2:31:36 AM | Active | cloudflare |
| 11/8/2025, 5:09:24 PM | Active | cloudflare |
| 11/7/2025, 2:43:30 PM | Active | cloudflare |
| 11/6/2025, 10:44:17 AM | Active | cloudflare |
| 11/2/2025, 8:40:52 PM | Active | cloudflare |
| 10/23/2025, 6:50:06 AM | Active | cloudflare |
| 9/22/2025, 4:40:29 PM | Active | cloudflare |
| 9/10/2025, 11:03:40 PM | Inactive | Unknown |
| 8/11/2025, 11:27:20 AM | Active | cloudflare |
| 7/25/2025, 10:25:29 AM | Active | cloudflare |
| 7/22/2025, 5:36:15 PM | Active | cloudflare |
| 7/13/2025, 8:27:05 AM | Active | cloudflare |
| 7/8/2025, 4:07:03 PM | Active | cloudflare |
| 7/7/2025, 9:39:29 AM | Active | cloudflare |
| 6/27/2025, 4:20:27 PM | Active | cloudflare |
| 6/21/2025, 1:50:25 AM | Active | cloudflare |
| 6/18/2025, 7:43:08 AM | Active | cloudflare |
| 5/25/2025, 7:52:19 PM | Active | cloudflare |
| 5/10/2025, 7:27:54 AM | Active | cloudflare |
| 5/8/2025, 1:27:50 AM | Active | cloudflare |
| 5/2/2025, 2:39:28 AM | Active | cloudflare |
| 4/26/2025, 2:35:28 AM | Inactive | Unknown |
| 4/22/2025, 4:22:36 PM | Inactive | Unknown |
| 4/5/2025, 7:44:14 PM | Inactive | Unknown |
| 3/30/2025, 2:19:36 AM | Inactive | Unknown |
| 3/23/2025, 2:24:34 AM | Inactive | Unknown |
| 3/13/2025, 1:06:31 PM | Inactive | Unknown |
| 2/27/2025, 9:47:21 PM | Inactive | Unknown |
| 2/21/2025, 3:24:47 AM | Inactive | Unknown |
| 2/1/2025, 5:02:19 AM | 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, CNAME, TXT 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
This page shows whether we could reach a website the last time we checked it. We also keep a record of when it went down and came back, so you can see whether an outage is new or has happened before. For each site we show:
- Website availability and response status
- Server software and configuration
- Meta information including titles and descriptions
- Historical uptime patterns
What this page reports
- Last status change: When we last saw a site switch between reachable and unreachable
- Last downtime: When a site was most recently seen down, and whether it has come back
- Server and meta information: The server software, page title and meta tags we last observed
We check a domain at most once a day and record an observation only when something changes, so these are the times a change was seen rather than the exact moment it happened. For continuous, minute-by-minute checks with alerting, use website monitoring.
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.