Free domains

Free domains today are almost always subdomains under someone else's parent domain rather than registered names of your own. DigitalPlat, DNSHE, isroot.in and pp.ua hand out names at no charge, and DNSHE lets you point the name at your own nameservers. freedns.afraid.org offers subdomains on a pool of domains shared by its users, and LocalCert issues names under localcert.net that public certificate authorities will sign, which helps for hosts on a private network.

The trade-off is control. The parent owner can change terms or shut the service down, and shared parent domains are sometimes flagged by email filters and security tools because of abuse by other users. Check whether a parent is listed on the Public Suffix List before relying on it for cookies or certificate rate limits. For a project that may grow, a cheap registered domain is safer; CatchDoms helps find expiring names, with 10 unlocked listings on its free plan.