WHOIS Monitoring: Your Guide to Tracking Domain Changes

What Are WHOIS and RDAP Records?

Think of WHOIS records like a domain's public profile. When someone registers a domain, they have to provide contact information, and that info gets stored in a database anyone can query. WHOIS has been around since the 1980s, and while it's showing its age, it's still the backbone of domain registration data.

RDAP (Registration Data Access Protocol) is the modern replacement. It does the same basic job but returns data in a structured format that's actually useful for automated tools. More on that in our WHOIS vs RDAP comparison.

A typical WHOIS record contains the registrant's name and contact details (though privacy services often mask these), the registrar who processed the registration, important dates like creation and expiration, the domain's nameservers, and status codes that tell you what's happening with the domain.

Why Monitor WHOIS Records?

WHOIS monitoring isn't just for domain investors sitting in dark rooms waiting for premium names to drop. There are real, practical reasons to keep an eye on domain records.

Protect Your Brand

Say you own acme-corp.com but someone registers acme-corp.net and starts setting up a phishing site. The WHOIS record change is often the first signal that something's happening. You can catch impersonators, trademark infringers, and typosquatters before they cause real damage.

Track Your Competitors

When a competitor changes their nameservers, they might be switching hosting providers or launching a new product. When they register new domains, they might be planning an expansion. This isn't corporate espionage; it's public information that savvy businesses monitor regularly.

Catch Domains Before They Drop

Domain investors watch WHOIS records to spot valuable domains that might become available. When a domain's expiration date passes without renewal, it enters a grace period before eventually dropping. Monitoring these changes gives you a head start on the competition.

Security and Compliance

If you're responsible for corporate domains, WHOIS monitoring helps you catch unauthorized transfers, expired domains that could be hijacked, and configuration changes that might indicate a compromised account.

What Changes Should You Watch For?

Not all WHOIS changes matter equally. Here's what actually deserves your attention:

• Registrant changes - The domain changed hands. This could mean a sale, a hostile takeover, or a routine internal transfer.
• Registrar changes - Someone moved the domain to a different registrar. Might be routine, might be someone trying to make a stolen domain harder to recover.
• Expiration date changes - Did it get renewed? Extended? Or is it creeping toward deletion?
• Status code changes - These are huge. A domain going from "active" to "pendingDelete" is about to become available. Learn more about reading WHOIS status codes.
• Nameserver changes - The domain is pointing somewhere new. Could be a hosting migration or something more suspicious.

How WHOIS Monitoring Works

The basic concept is simple: query a domain's WHOIS record regularly, compare it to the previous version, and flag any differences. The execution is where things get interesting.

You can't just hammer WHOIS servers with requests. They'll rate-limit you or ban your IP entirely. Different TLDs have different WHOIS servers with different response formats. Some registrars add extra fields. Privacy services return masked data. It's a mess.

That's why most people use a monitoring service rather than building their own. A good service handles the technical complexity, normalizes the data across TLDs, and delivers clean notifications when something changes.

shadom.co monitors both WHOIS and RDAP data, since RDAP is gradually replacing WHOIS and many TLDs now serve better data through RDAP endpoints.

Setting Up Effective WHOIS Monitoring

Whether you're tracking a handful of domains or thousands, here's how to get the most out of WHOIS monitoring:

Start With Your Own Domains

Sounds obvious, but you'd be surprised how many companies don't actively monitor their own domain portfolio. Set up alerts for all domains you own, including variations and common misspellings of your brand.

Add Domains You Want to Acquire

Got your eye on a domain that's currently registered? Monitor it. You'll know the moment the owner lets it lapse or puts it up for sale. Our change monitoring guide covers the best strategies for acquisition alerts.

Filter the Noise

Some changes don't matter. A registrar updating their administrative contact email isn't actionable for most people. Good monitoring tools let you filter by change type so you only get alerts that matter.

WHOIS Monitoring Deep Dives

Ready to go deeper? Check out these detailed guides:

• WHOIS vs RDAP: Understanding the Differences

  Why RDAP is replacing WHOIS and what it means for domain monitoring.

• How to Read WHOIS Records

  Decode status codes, understand each field, and read between the lines.

• WHOIS Change Notifications

  Set up alerts for the changes that matter to your business.