Is it possible to register domains for free by setting up my own DNS server?
For instance, if I create a DNS server at home and add domains myself, will I be able to obtain them for free? Would other users have access to this domain as well?

Sites that have your DNS server installed in their settings will be accessible. However, this will only apply to a limited number of sites, and those with your domain name will not be searchable by search engines.
The reason behind this is that they do not use your DNS server, hence unable to locate your domain's existence and its address.

The Internet has root DNS servers which act as gatekeepers for first-level domains that are then passed down to lower level zones in a hierarchical manner. The entire DNS system is interconnected through this hierarchy.

If you happen to be a popular registrar, it will not be financially feasible for you. Freenom is one registrar that falls under this category. However, I had issues with their domain as my Google site was not indexed for half a year.

pros and cons of using popular registrars versus lesser-known ones. While the former may offer more services and recognition, it can also come with higher costs and potential drawbacks such as slow indexing. On the other hand, lesser-known registrars may be more affordable but may lack the same level of trust and credibility. Ultimately, it's important to do research and weigh the options before committing to a registrar for your website.

You could technically set up your own DNS server at home, but registering domains isn't that simple.

When you want a domain name, you typically need to register it through a domain registrar. This is a service that allows you to reserve a domain (like example.com) for a certain period, usually for a fee. The DNS only translates domain names into IP addresses. You can run a DNS server, but if you want to own a domain name, you need to register it properly.

If you just create your own DNS server and try to add a domain name without registering it, no one else would be able to access it unless they point their DNS settings to your server. This means that your domain would be only accessible to users who know about your DNS server and configure their settings to use it. It's like creating a private network; it's not public and won't be recognized by the global DNS system.

If someone else registers the same domain name with an official registrar, you won't have any rights to it, even if you have created a DNS entry that points to it. The global domain name system has to be maintained and confirms who has the rights to use certain domain names.
While you can run your own DNS server, you can't get true domain ownership for free just by setting one up. You need to go through registration processes to have a publicly accessible and officially recognized domain.

Setting up your own DNS server at home won't let you register domains for free - that's not how the TLD ecosystem works. You can't just add domains yourself and expect ICANN to recognize them without paying for registration through a legit registrar; it's all about authoritative delegation and WHOIS records.

Sure, you could run a private nameserver for internal use, like for a home network, but globally, other users won't access it unless you delegate it properly, and even then, squatters and registrars will block free grabs. Use tools like BIND for your authoritative server, but remember, free domains are a myth - always pay for that prime TLD real estate.