How DNS Works: What Happens When Someone Visits Your Website

When someone types your domain into a browser, a series of lookups happens before your site appears — and it takes milliseconds. Understanding this sequence matters when you’re configuring hosting, moving between providers, or troubleshooting a site that isn’t resolving correctly.

The lookup sequence: The browser checks its local cache first. If nothing is cached, it asks a recursive resolver — usually your ISP’s or a public one like 1.1.1.1. The resolver works up the hierarchy: root nameservers -> top-level domain nameservers (for .com, .io, etc.) -> your domain’s authoritative nameservers -> the final answer: an IP address.

DNS records that matter for hosting: An A record maps your domain to an IPv4 address. A CNAME creates an alias pointing one name to another. MX records direct email. TXT records are used for domain verification and SPF/DKIM email authentication.

Propagation: When you update DNS records, the change doesn’t take effect instantly everywhere. Records have a TTL (Time To Live) — a value in seconds that tells resolvers how long to cache the answer. A TTL of 3600 means resolvers hold the old answer for up to an hour before fetching a fresh one. Lower your TTL before making changes if you want faster propagation.