An NS (Name Server) record tells the internet which DNS servers are authoritative for a domain. In simple terms, it dictates exactly which servers hold the actual DNS records (like A, MX, and TXT records) for your website.
Did you recently change hosting providers or move to a CDN? Check which nameservers are currently active.
The DNS system is strictly hierarchical. When you register a domain like example.com, the registry for the .com Top Level Domain (TLD) needs to know who is in charge of your specific domain. You provide your registrar with your Nameservers (e.g., ns1.cloudflare.com and ns2.cloudflare.com).
The TLD publishes these NS records. When a user tries to visit your website, their browser asks the TLD: "Who knows the IP address for example.com?" The TLD responds with your NS records, effectively delegating the authority to your chosen DNS provider. The browser then queries your specific nameservers to get the final answer.
DNS requires redundancy to keep the internet stable. If you only had one nameserver and it crashed, your entire domain (website, emails, subdomains) would instantly go offline. Registrars and RFC standards require at least two nameservers (e.g., ns1 and ns2), preferably hosted on different physical networks.
There are two places NS records exist: at your registrar (the "parent" TLD zone) and inside your actual DNS hosting dashboard (the "child" zone). For a healthy DNS setup, the nameservers listed in both places should match exactly. If they don't, it can cause intermittent resolution errors.
Unlike A or TXT records where you can lower the TTL yourself, the TTL for NS records at the TLD level is controlled by the registry (often 24 to 48 hours). Therefore, changing your authoritative nameservers is the slowest DNS change you can make, and propagation can take up to two full days globally.