SSL Certificate Check: Verify Any Website's Security in Seconds
An SSL certificate check tells you whether a website's HTTPS connection is properly configured.
DomScan
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Guides, product updates, domain research, DNS explainers, and technical breakdowns from DomScan.
IP Reputation: How Blacklists Work and How to Check Yours
IP reputation determines whether your email reaches the inbox or gets silently dropped. This guide explains how DNS-based blacklists work at the protocol level, which lists matter most, and how to check, delist, and prevent future listings.
Reverse MX Lookup in DomScan: Scope, Limits, and Safer Use
DomScan's deprecated Reverse MX API searches a short-lived cache built from prior DNS lookups. Learn exactly what a result means, where gaps come from, and how to verify each lead.
Reverse IP lookup: interpreting observed domains on an IP
Reverse IP lookup is a dataset query, not a PTR lookup. This guide explains what DomScan's deprecated seven-day observation index can and cannot show for IPv4 and IPv6 addresses.
IP Tracker: How IP Geolocation Actually Works Under the Hood
The phrase "IP tracker" suggests you can follow someone's movements in real time. That is a movie myth. IP geolocation maps addresses to approximate locations using BGP routing data, active latency probing, and crowdsourced ground truth.
MAC Address Lookup: Identify Device Manufacturers by OUI Prefix
Every network interface has a 48-bit MAC address burned in at the factory. The first three bytes — the OUI — identify the manufacturer.
Domain lifecycle: what expiration, redemption, and deletion actually mean
A domain's expiry date is not a universal drop date. This guide explains the gTLD baseline, registrar variation, ccTLD exceptions, recovery states, transfer risks, and practical renewal controls.
RDAP vs WHOIS in 2026: Protocols, Policy, Coverage, and DomScan Endpoints
RDAP is now definitive for contracted gTLDs, but WHOIS still matters for three gTLD exceptions, many ccTLD workflows, and compatibility. This guide separates protocol, policy, coverage, and DomScan endpoint behavior.
WHOIS API in 2026: DomScan endpoints, RDAP sources, and safe integration
DomScan's WHOIS API is RDAP-first, with traditional WHOIS and DNS fallbacks where coverage requires them. This guide documents the live endpoints, response sources, cache behavior, costs, privacy limits, and error handling.
WHOIS Privacy in 2026: Redaction, Proxy Services, and Disclosure
ICANN's current policy separates public from nonpublic registration data. This guide explains redaction, privacy and proxy services, RDRS, RDAP, and the limits of domain lookups.
Comparing domain lookup APIs in 2026: scope, pricing, and freshness
A sourced comparison of SecurityTrails, WhoisXML API, DomainTools, Shodan, and DomScan, with the limits of each product made explicit.
WHOIS History After the RDAP Cutover: How Domain Snapshots Work
Historical registration snapshots can show when a registrar, nameserver, status, or expiry date changed. This guide explains what those observations prove, what they do not, and how DomScan coverage works.
WHOIS domain search after the RDAP cutover: what registration data can tell you
A WHOIS domain search no longer means querying one plaintext directory for a website owner. For generic domains, RDAP is now the definitive source, and the public result usually describes registration state rather than personal identity.
IP WHOIS and RDAP: find the registered network holder
IP registration data identifies the network holder and operational contacts for an address range. It does not identify a cloud customer, physical server, or individual user.
WHOIS and RDAP lookup: a practical guide to domain registration data
RDAP is now the definitive source for gTLD registration data, while WHOIS remains in a smaller legacy role. Learn to read dates, status codes, nameservers, DNSSEC, and privacy signals without treating them as proof of ownership.
TXT Records Explained: SPF, DKIM, DMARC and Beyond
TXT records started as a place for human-readable notes in DNS. They now carry the machine-critical data that decides whether your email arrives, your domain is verified, and your security policies are enforced.
A Record vs CNAME: When to Use Each DNS Record Type
A records map hostnames to IP addresses. CNAMEs alias one hostname to another. The choice between them determines how CDN routing, SSL issuance, email delivery, and DNS migrations actually behave in production.
NS Record Check: How to Verify Nameserver Configuration
NS records are the delegation chain of DNS. Get them wrong and your entire domain goes dark. Here is how to check, diagnose, and fix nameserver configuration problems before they become outages.
MX Record Lookup: How Email Routing Works
When you send an email, your mail server queries MX records to find which servers accept mail for the destination domain. This guide explains MX priority, fallback chains, common configurations, security implications, and troubleshooting.
Understanding DNS Servers: Types, Setup, and Troubleshooting
DNS server means different things depending on context. This guide breaks down the four types, compares public resolvers, walks through configuration on every major OS, and covers troubleshooting and security.
DNS Leak Test: What It Is and Why It Matters for Your Privacy
A DNS leak exposes every domain you visit to your ISP, even when you think a VPN or encrypted resolver is protecting you. Learn what causes DNS leaks, how to test for them, and how to fix them permanently.
IP address lookup: geolocation, ASN, privacy, and hard limits
A deeper account of what an IP address can reveal through allocation records, BGP, RPKI, geolocation, and DNS, plus the effects of anycast, NAT, VPNs, and reassignment.
DNS Checker: A Rigorous Guide to Verifying DNS Changes
A DNS result is one observation, not proof of global propagation. Learn how to check authority, delegation, caches, DNSSEC, and real client paths without overclaiming.
What Is a DNS Lookup and How Does It Work?
Every URL you visit starts with a DNS lookup that finishes in under 100 milliseconds. This guide walks through the full resolution chain, record types, caching, common errors, and security signals.
How to read an IP lookup without overclaiming
A practical guide to DomScan IP results: geolocation estimates, ASN context, PTR and FCrDNS, security flags, raw RDAP follow-up, and the limits of reverse IP evidence.
How Much Is a Domain Worth? The Factors That Determine Domain Value
Domain valuation is part language, part market context, and part buyer fit. This guide explains what actually drives domain value and how to interpret automated appraisals realistically.
Bulk WHOIS Lookup: How to Research Thousands of Domains Efficiently
Bulk WHOIS work is less about sending thousands of queries than about turning inconsistent registration data into something you can actually analyse. This guide explains how to do that well.
Domain Monitoring: Build an Expiry and Availability Workflow That Works
Good domain monitoring starts with clear ownership and reliable registration checks. Learn what to automate, what to review separately, and how DomScan fits.
Domain Expiration Monitoring: How to Never Lose a Critical Domain
Domain loss is usually an ownership and process failure long before it becomes a registrar-date problem. This guide explains how to monitor critical domains so they do not quietly slide toward lapse.
Cybersquatting: Legal Protections, UDRP Process, and Domain Recovery
Cybersquatting is a legal and operational problem. This guide explains what actually counts as cybersquatting, when UDRP is the right path, and how to prepare stronger recovery evidence.
Domain Reputation: What It Is, Why It Matters, and How to Improve It
Domain reputation is the accumulated trust judgment attached to your domain identity. This guide explains what feeds it, how it degrades, and what operators can do to improve it without chasing myths.
Attack Surface Management: A Complete Guide for Security Teams
Attack surface management is the work of turning forgotten internet-facing assets into observable, owned, and prioritised risk. This guide explains how domain-led discovery makes that possible.
Typosquatting: How Attackers Exploit Domain Misspellings and How to Fight Back
Typosquatting is a trust-abuse problem disguised as a naming problem. This guide explains how attackers use typo variants, why they matter operationally, and how defenders can reduce the risk.
Wildcard vs. Multi-Domain SSL Certificates: Which One Do You Need?
Wildcard and multi-domain certificates solve different trust-scope problems. This guide explains the coverage, operational tradeoffs, and blast-radius implications behind each model.
SSL Certificate Monitoring: How to Prevent Costly Expiry Outages
Certificate monitoring should cover trust drift, deployment mistakes, and unexpected issuance, not merely one date on a calendar. This guide explains how to build a monitoring routine that prevents outages.
What Is an SSL Certificate Chain? How Certificate Trust Works
Browsers trust chains, not isolated leaf certificates. This guide explains roots, intermediates, and why certificate trust fails in production even when a certificate looks “valid.”
DNS History for Investigations: What Observation Logs Can and Cannot Prove
DNS history can reveal changes in observed records, but only when you understand the dataset. Learn how to investigate timelines without treating clues as proof.
Reverse DNS Lookup: What It Is, How It Works, and Why It Matters
Reverse DNS is more than a curiosity in a mail header. This guide explains how PTR records work, why reverse lookups matter for mail and investigations, and where teams misread them.
How Long Does DNS Propagation Take? The Technical Reality
DNS propagation is not one global timer. It is the practical effect of caches, TTLs, resolver behaviour, and where the change was made. This guide explains what actually determines visibility after a DNS update.
DNS Record Types Explained: A, AAAA, CNAME, MX, TXT, and Beyond
DNS records are easy to define and much harder to operate well together. This guide explains the major record types, what question each one answers, and where teams create avoidable confusion.
Business Email Security in 2026: Threats, Standards, and Implementation Guide
Business email security sits at the intersection of domain identity, workflow trust, and brand protection. This guide explains how to build controls that reduce spoofing, impersonation, and payment-risk exposure.
SPF Record Best Practices: Avoiding the 10-Lookup Limit and Common Mistakes
SPF becomes fragile when it turns into a dumping ground for vendors. This guide explains how to keep sender authorization records within limits and maintainable as the mail stack grows.
How Email Authentication Impacts Deliverability: What Every Domain Owner Should Know
Deliverability is easier when domain identity is boringly coherent. This guide explains how SPF, DKIM, and DMARC influence receiver trust and why weak authentication makes inbox placement harder.
How to Read and Analyze DMARC Reports: A Practical Guide
DMARC reports are useful only when they become operational decisions. This guide explains what aggregate reports actually show, how to triage them, and how to use them for policy rollout.
The Complete Guide to SPF, DKIM, and DMARC: How Email Authentication Works
SPF, DKIM, and DMARC are not separate checkboxes. They form one operating system for mail identity, authorization, and policy. This guide explains how the stack works and how to deploy it safely.