Rocket Validator now uses fixed IP addresses, so you can safely add them to your firewall or CDN allowlist.
Until now our addresses could change, which made IP-based rules unreliable. Now, requests from the link spider, HTML and accessibility checkers, and screenshot system come from the same four IPv4 and four IPv6 addresses.
You can find the full list at rocketvalidator.com/ips.
There's also a plain text version at /ips.txt, with one address per line, which is handy for scripts and firewall configs.
