Uptime checks will make regular requests to a website, an API endpoint, or a TCP service and alert you if it doesn’t respond correctly.

Worldwide servers

Uptime checks are run from 5 servers worldwide. Downtime is verified from all other servers and reported if there is agreement.

Allowing our servers

If you need to need to add our check servers to your allowlist (whitelist) then there are a couple of ways you can do that:

  1. Allow the request based on the string sitesure which will always appear in the User-Agent header
  2. Allow the request based on the hostname (You can retrieve the IP addresses via A and AAAA DNS queries)
  3. If you must use IP addresses manually, then use the list below (least preferred option as it won’t handle changes to our IP addresses)
Server Location IPv4 address IPv6 address
Amsterdam, Netherlands 2a05:f480:1400:2fac:5400:4ff:fe70:625
Bangalore, India 2401:c080:3000:2047:5400:4ff:fe53:e40b
Johnnesburg, South Africa 2a05:f480:3000:2ca4:5400:4ff:fe53:da98
Los Angeles, United States 2001:19f0:6001:615:5400:4ff:fe70:5b0
Melbourne, Australia 2401:c080:2000:2e93:5400:4ff:fe53:db67