WhoisXML API vs Domainyze: query the data or watch the names
Last updated: November 2026
WhoisXML API answers a lookup when you ask, at a scale and depth of history Domainyze does not try to match. Domainyze keeps reading the registry for the names you add and tells you when one changes, so you do not build the watcher yourself.
WhoisXML API is a provider of domain, DNS and IP data APIs: WHOIS across more than 7,500 TLDs and ccTLDs, WHOIS History, Reverse WHOIS, DNS and IP lookups, priced in credits, with 500 free API requests to start and a shared credit pool from $129/month. Domainyze is a domain monitor: it reads the live registry for the names you add, on a schedule, and alerts you by email, Slack, Discord or signed webhook when registration, lifecycle stage, DNS or SSL changes. Its REST API and MCP server read that monitored state and run lookups on any name. Pick WhoisXML for bulk data, history and reverse search; pick Domainyze when the job is watching a known set of domains.
A data API vs a monitor
WhoisXML API is a database you query. Domainyze is a watcher you subscribe to. Most teams searching for an alternative want one of the two, not both.
WhoisXML API: answers a query
Send a domain, get its WHOIS record back as JSON or XML. It also sells WHOIS History, Reverse WHOIS, DNS and IP lookups, and holds more than 28 billion WHOIS records.
Domainyze: keeps watching
Add a domain once. Domainyze reads the registry on a schedule, names its lifecycle stage, forecasts the drop on names you want, and alerts you on the change.
When you might use both
Research a market or an owner with WhoisXML's history and reverse search, then hand the names that matter to Domainyze to watch.
Pulling records vs being told
A lookup API tells you what is true now. Knowing when it stops being true means polling it, storing the last answer and diffing them yourself.
With a data API, you poll
Expiry, registrar and nameserver changes surface only when you ask again. The schedule, the storage, the diff and the alert are code you write and run.
With Domainyze, the change comes to you
Domainyze runs the checks, keeps the previous answer and sends the difference to email, Slack, Discord or an HMAC-signed webhook.
What a change means
Registrar, nameservers, EPP status, lifecycle stage, DNS records and certificate expiry, each with its own alert, plus a daily digest of upcoming renewals.
{
"event": "ssl.invalid",
"domain": "api.sideproject.com",
"data": {
"issuer": "Let's Encrypt",
"days_remaining": -1,
"status": "EXPIRED"
}
}Where WhoisXML API is the right tool
Some questions need a dataset, not a monitor. On these, WhoisXML API does what Domainyze does not.
WHOIS history
Who owned a domain before, and when it changed hands, from years of stored records. Domainyze only records what it has seen since you added the name.
Reverse WHOIS and bulk data
Every domain registered to an email or organisation, bulk lookups and data feeds across more than 7,500 TLDs and ccTLDs. Domainyze has no reverse search and sells no data feed.
What Domainyze reads instead
The live registry, RDAP first with a WHOIS fallback, for each name you add or look up. Fresh for the names you care about, not a record of everyone else's.
Watching 200 domains, two ways
The common reason to reach for a WHOIS API is to keep an eye on a portfolio. Here is what that takes on each.
Domainyze
- Import your domains from a CSV or add them through the API.
- Domainyze reads each registry on a schedule and stores the result.
- A change or an upcoming expiry raises an alert on the channel you chose.
- Your code reads current state through the REST API or MCP when it needs it.
WhoisXML API
- Get an API key and pick a credit package.
- Write a job that queries each domain on a schedule.
- Store each response and diff it against the last one.
- Build the alerting, retries and expiry thresholds yourself.
What each one costs
WhoisXML API charges per query. Domainyze charges per domain watched, and the checks are included.
WhoisXML API: credits per query
from $129/monthA shared credit pool across its APIs starts from $129/month, with per-product packages and 500 free API requests to try it. Polling a portfolio spends credits on every check.
Domainyze: per domain, checks included
$39/month500 domains monitored with the REST API at $39/month, plus 1,500 tool lookups a month on any name, shared with the MCP server. MCP alone is available from $19/month.
And a free tier to start
Domainyze monitors 5 domains free, permanently, and the public tools run single lookups with no account.
Domainyze vs WhoisXML API head-to-head
WhoisXML API wins on data depth and breadth; Domainyze wins on watching and alerting.
| Capability | Domainyze Us | WhoisXML API |
|---|---|---|
| Core function | Domain monitoring and alerts | Domain, DNS and IP data APIs |
| Primary role | Tells you when your domains change | Answers a lookup when you ask |
| WHOIS or RDAP lookup on any name | ||
| Re-checks your domains on a schedule | Built in, per domain | Separate monitor products |
| Lifecycle stage and drop forecast | ||
| Change alerts to Slack, Discord, signed webhook | Every alert type, every channel | You build it on the API |
| Historical WHOIS records | ||
| Reverse WHOIS search | ||
| MCP server for AI assistants | ||
| What you pay for | Per domain watched, checks included | Credits per query |
Which should you use?
It depends on whether the question is about the internet or about your domains.
Choose Domainyze if…
Use Domainyze when you have a set of domains to keep an eye on: your own portfolio, a client list, or names you want. It does the scheduling, storage, diffing and alerting, and its REST API and MCP server expose the result.
Choose WhoisXML API if…
Use WhoisXML API when you need data Domainyze does not hold: WHOIS history, reverse WHOIS, bulk lookups or feeds across more than 7,500 TLDs and ccTLDs. For research, threat intelligence or enrichment at volume, it is the stronger tool.
Frequently Asked Questions
Common questions about Domainyze and WhoisXML API.
What is the difference between Domainyze and WhoisXML API?
WhoisXML API sells domain and IP data you query by API. Domainyze monitors the domains you add, re-checks them on a schedule and alerts you when something changes. One is a data source, the other is a watcher.
Is Domainyze a WhoisXML API alternative?
For monitoring a known set of domains, yes: you get the checks, history of changes and alerts without writing the poller. For WHOIS history, reverse WHOIS or bulk data, no. Domainyze does not hold those datasets.
Does Domainyze have a WHOIS API?
Yes. The REST API includes WHOIS, availability, expiry, DNS and SSL lookups on any name, read live from the registry, plus read and write access to the domains you monitor. Lookups come from a monthly budget shared with the MCP server.
How much does WhoisXML API cost?
It is credit-based: 500 free API requests to start, and a shared credit pool from $129/month. Domainyze is free for 5 domains; the REST API comes with 500 domains at $39/month. Figures reviewed November 2026, so confirm current rates on their site.
Can I get WHOIS history from Domainyze?
Only for what Domainyze has observed since you added a domain: each registrar, nameserver and status change it saw. It has no records from before that.
Do both have an MCP server?
Yes. WhoisXML API offers one for its data. Domainyze's MCP server lets Claude, Cursor and other assistants read your monitored domains, alerts and DNS, and run lookups on any name.
How do I get alerted when a domain's WHOIS changes?
With a data API you poll it and diff the answers yourself. With Domainyze you add the domain and choose a channel; a registrar, nameserver or status change raises an alert. For a one-off check, the free WHOIS lookup needs no account.
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