ssltest

ssltest is the checker behind ssltest.com. Each check reads the TLS certificate and settings of one host, along with its robots.txt and the headers of its home page.

User agent

Mozilla/5.0 (compatible; ssltest/1.0; +https://ssltest.com/bot)

Blocking ssltest with robots.txt

ssltest reads robots.txt before each check and stops when the rules disallow the check. These lines in robots.txt block ssltest:

User-agent: ssltest
Disallow: /

ssltest still fetches the robots.txt file itself to read these rules, as section 2.2.2 of RFC 9309 describes. A DNS record blocks every check of a domain as well, as described on the opt-out page.

IP addresses

Requests from ssltest come from the addresses below, also available as ips.json. The addresses change over time, so robots.txt is the more reliable way to block ssltest.

5.75.226.1
5.78.127.133
46.62.245.131
46.224.4.70
46.224.90.139
51.77.109.222
51.83.226.162
54.38.224.71
57.128.7.169
57.128.110.86
62.238.123.142
64.23.130.26
64.227.149.192
107.170.61.210
134.199.172.113
138.68.56.192
138.197.95.25
138.197.131.120
143.110.166.163
143.110.216.115
146.190.166.40
157.230.122.46
157.245.77.242
157.245.223.188
159.203.131.187
161.35.63.154
162.243.103.111
162.243.208.209
165.227.168.138
165.232.163.233
167.71.155.91
167.99.224.69
167.99.242.104
170.64.227.193
174.138.11.112
178.128.102.89
178.156.183.239
206.81.6.18
209.38.101.36
2a01:4f8:c012:c926::1
2a01:4f9:c012:f1a8::1

Contact

Questions about ssltest go to fili@ssltest.com.