Domain Attribution API

Intelligence that
shows its work

Query a domain. Get the real operator, not the CDN, not REDACTED FOR PRIVACY. Every confidence score breaks down into the signals behind it so you can verify the answer yourself.

Analyze your first domain See the docs

98.33%

Accuracy

12 signals

Fused

See why

Not just who

signal.org 9/12

Signal Technology Foundation

61.0% confidence

WHOIS: REDACTED

Content 19.5%

SSL/CT 15.5%

HTTP 12.0%

The problem

You're making decisions on incomplete data

WHOIS is gone. CDNs mask 40% of the web. And the tools that claim to fill the gap won't show you how they got their answer.

WHOIS Returns Nothing

GDPR redacts ownership fields. ICANN's RDAP transition made things worse. Your primary intelligence source now returns REDACTED FOR PRIVACY.

CDNs Hide the Operator

Cloudflare, AWS CloudFront, and Fastly sit in front of 40% of all domains. Single-source tools tell you it's behind Cloudflare. You already knew that.

Scores Without Evidence

Other platforms give you a number. No signal weights. No source breakdown. When the score is wrong (and it will be), you can't figure out why.

How it works

Multiple sources. One scored answer.

A single query checks every available intelligence source concurrently. Results are fused, weighted, and decomposed into a full evidence chain.

Query

Send any domain. All intelligence sources checked concurrently in under 3 seconds.

Score

Signals weighted, correlated, and fused into per-entity confidence scores.

Decompose

Every score breaks down to raw signal contributions. Full evidence chain.

Interactive demo

Try it now

Enter a domain to see scored attribution with per-signal breakdown

Real results

We publish our accuracy, including where we're wrong

Real attribution results on real domains. A tool you can't audit is a tool you can't trust.

signal.org 7/8 sources

Signal Technology Foundation

nonprofit

Confidence 61.0%

framework.computer 8/8 sources

Framework Computer Inc

corporation

Confidence 72.0%

mullvad.net 6/8 sources

Mullvad VPN AB

corporation

Confidence 54.0%

darkpool-ind.com 3/8 sources

Unknown

registrar

Confidence 4.0%

Parked domain with no content, SSL, or identifying infrastructure

Built for

Teams that need answers they can verify

Security Teams

Phishing attribution, threat infrastructure mapping, incident response evidence

Legal & IP

UDRP dispute evidence, signed attribution certificates, trademark enforcement

Researchers

Infrastructure mapping, OSINT investigations, vulnerability disclosure

Compliance

KYC domain verification, vendor screening, M&A domain portfolio audits

12sources

fused per query

98.33%

benchmark accuracy

<3s

full analysis

374M+

domains searchable

Capabilities

Domain attribution you can put in a report

Works When WHOIS Doesn't

GDPR-redacted domains, privacy-proxied registrations, CDN-masked origins. WhoisGenius finds the real operator when single-source tools return nothing.

Evidence You Can Cite

Every confidence score decomposes into the signals behind it. Include the full evidence chain in reports, filings, or investigations. Not just a number.

Signed Certificates

Generate tamper-proof attribution certificates for legal proceedings, compliance documentation, or UDRP domain disputes.

98.33% Accuracy

Benchmarked on real domains across 6 difficulty categories, including CDN-masked, GDPR-redacted, and multi-tenant hosting. We publish the methodology and the failure cases.

AI for Edge Cases

When the evidence is ambiguous, optional AI enrichment resolves entities and explains its reasoning in plain language. Zero cost when not needed.

Answers in Under 3 Seconds

All intelligence sources checked concurrently. One API call, one response, full evidence chain. Ready for automation, bulk analysis, or real-time workflows.

Historical Intelligence

v2.1

Domains change hands. Infrastructure moves. WhoisGenius now tracks the full history so you can see who operated a domain last year, not just today.

Passive DNS reveals infrastructure history and sole IP tenancy

WHOIS ownership timelines show when operators changed

GDPR-redacted field reconstruction recovers hidden registrant data

CDN-gated correlation suppresses false positives from shared hosting

Portfolio Discovery

v2.1

You found one domain. But what else does that entity run? Reverse WHOIS searches across 374M+ domains to map the full portfolio.

Reverse WHOIS across 374M+ domains by name, email, or org

Answer "what else does this entity run?" in a single query

Connect domains across subsidiaries, acquisitions, and rebrands

Infrastructure correlation validates portfolio membership

Pricing

Simple, transparent pricing

Start free. Scale when you need to.

DomainTools starts at $50,000/year.

Free

$0/month

500 queries / month

500 queries / month
Rule-based scoring
Summary results
1 API key
Community support

Get started free

First result in 30 seconds

Three lines from signup to your first scored domain attribution.

No SDK required. Any HTTP client works.

terminal

# Analyze any domain
curl https://api.whoisgeni.us/analyze/signal.org \
  -H "X-API-Key: YOUR_KEY"


  "domain": "signal.org",
  "top_entity": 
    "name": "Signal Technology Foundation",
    "confidence": 0.610
  ,
  "signals": [
     "source": "Content",    "contribution": 0.195 ,
     "source": "SSL/CT",     "contribution": 0.155 ,
     "source": "WHOIS",      "contribution": 0.000 
  ]

See who really operates any domain

500 free queries per month. Full evidence chain on every result.

No credit card. No password. Just a magic link to your inbox.

Start analyzing domains See use cases

Intelligence that shows its work