Domain intelligenceSEARCH / RESOLVE / EXPLORE

One domain.
Every connection.

Follow a domain through its subdomains, certificate history,
and DNS records. A little digging goes a long way.

Ctrl K

Try a domain

No token required1,000 requests / dayAlways free

ILLUSTRATIVE NETWORKONE DOMAIN. EVERY CONNECTION.

There’s more to a domain.DISCOVER. RESOLVE. UNDERSTAND.

A little curiosity.
A lot of possibilities. Certificate intelligence Deduplicated by design DNS over HTTPS An API for everything

+ FROM A NAME TO A NETWORK

Names leave traces.
Follow them.

A hostname, a certificate, a date. Put them together and a domain starts to tell its story.

/01

Go beneath the surface.

Discover the hostnames connected to a domain through its public certificate history.

FOLLOW THE CONNECTIONS

/02

One name. One result.

Repeated certificates come together in a single, clean record. Keep the history. Lose the duplicates.

LESS REPETITION, MORE CLARITY

/03

The latest, up front.

Names with the latest certificate observations rise to the top, with first and last seen dates alongside.

ORDERED BY LAST OBSERVED

+ YOUR TERMINAL WILL FEEL AT HOME

From this workspace.
To your command line.

Pipe names into a script. Save a snapshot. Build your own view. The same results, in the format your tools already speak.

JSON, TXT & XML Detailed or simplified No key, no friction

Open the API reference 1,000 requests / IP / day. On us.

a little request. a bigger picture.

$curl "https://resolvify.xyz/api/v1/search?domain=example.com&format=json&view=detailed"

EXAMPLE · EXCERPT

{
 "domain": "example.com",
 "total": 3,
 "results": [
    {
 "hostname": "api.example.com",
 "lastSeen": "2026-10-20T09:41:00.000Z",
 "certificateCount": 12
    }
  ]
}

HTTPS · REST · v1Explore the response schema

+ BEFORE YOU HIT ENTER

A few things
worth knowing.

Find more in the docs

01What can I discover with Resolvify?+

Start with an apex domain, such as example.com, to find names observed in public TLS certificates. Switch to DNS lookup to check A, AAAA, MX, NS, TXT, CNAME, SOA, or CAA records for a domain or subdomain.

02Is a discovered subdomain always online?+

A certificate is a historical observation, not proof that a service is currently running. First and last observed dates describe certificate history. Use the DNS lookup to check current DNS answers; cached results include their query date.

03Do I need an account or API key?+

No. The explorer and API share a daily allowance of 1,000 requests per IP, resetting at midnight UTC. A short-term limit of 30 requests per minute keeps things fair. Cached responses and different output formats use the same allowance.

04How fresh are the results?+

Subdomain results are cached for up to 24 hours to keep repeat searches fast. If a new lookup cannot finish, a saved snapshot up to seven days old may be returned and is clearly marked. DNS records follow their TTL within bounded cache windows.

05Which DNS resolver does Resolvify use?+

Our domain resolver uses the Cloudflare resolver over encrypted DNS over HTTPS. Request a specific DNS record type to inspect addresses, mail routing, nameservers, and more. Certificate-based subdomain discovery is a separate view of a domain’s history.

06Can I use the data in my own tools?+

Absolutely. Use our public REST API for JSON, plain text, or XML, with detailed and simplified responses. Export the visible results from the explorer or use API pagination for larger result sets.

PICK A NAME. FOLLOW ITS TRAIL.

You have a name.
Follow the connections.

Let’s find it

One domain.Every connection.

Names leave traces.Follow them.