Introduction
SecurityTrails vs SurfaceGuard is a comparison between two different external visibility jobs.
SecurityTrails is strongest when teams need current and historical internet asset intelligence: DNS records, passive DNS-style history, WHOIS, IP context, subdomains, associated infrastructure, and API enrichment for investigations or security automation.
SecurityTrails should be treated as DNS and internet asset intelligence, not only passive DNS. Passive and historical DNS are major strengths, but the API also covers IP, WHOIS, company, asset, and exposure data.
SurfaceGuard, branded as Surface Guard on its official site, is positioned as an external attack surface monitoring product. Its public site highlights monitored domains, 24/7 scanning, automatic asset discovery, AI-assisted risk classification, reports, alerts, dashboards, integrations, and subdomain takeover monitoring.
The decision is not only about which tool finds more names. It is about whether your team needs a data-intelligence source for investigation or an operational monitoring workflow for active external exposure.
TL;DR — SecurityTrails vs SurfaceGuard quick comparison
Choose SecurityTrails when your main need is DNS and internet asset intelligence: historical DNS, WHOIS, IP and domain enrichment, subdomain discovery, related-infrastructure research, and API-driven investigation.
Choose Surface Guard when your main need is monitored-domain EASM: external surface monitoring, risk classification, reports, alerts, integrations, dashboards, and operational remediation guidance.
| Category | SecurityTrails | SurfaceGuard |
|---|---|---|
| Best fit | Threat intelligence, OSINT, investigation, DNS history, data enrichment, passive discovery, and security automation workflows | Security teams that want active external attack surface monitoring with alerts, reports, dashboards, and remediation-oriented workflow |
| Primary job | Provide current and historical internet asset data through web and API workflows | Continuously monitor external attack surface exposure and notify teams about risks |
| Core strength | Historical DNS, current DNS, WHOIS, IP intelligence, subdomain data, related-infrastructure research, and API enrichment | Monitored-domain EASM, subdomain takeover monitoring, alerting, reports, dashboards, AI-assisted classification, and integrations |
| Monitoring model | Useful for enrichment and investigation; project, asset, API, and internal automation workflows can support monitoring depending on implementation | Public site describes 24/7 scanning, automatic asset discovery, weekly or daily reports, and real-time alerts on Business |
| Passive vs active | More data-intelligence, historical, and passive-discovery oriented | More active monitoring and workflow oriented |
| Remediation workflow | Primarily provides data and context that analysts or internal tools must operationalize | Public site says it classifies risks, ranks priorities, suggests actions, and sends alerts |
| Pricing transparency | Public pricing page lists Professional, Business, and Enterprise plans; buyers should verify current limits and access directly | Public site lists StartUp, Business, and Custom plans with monitored-domain limits |
| Main caution | Do not treat DNS and asset intelligence as a complete remediation or monitoring program by itself | Scanner-level coverage is less publicly documented, so buyers should verify exact test categories and evidence quality |
What each tool actually does
SecurityTrails and Surface Guard overlap around external asset visibility, but they are not the same type of product.
SecurityTrails is closer to an internet intelligence data source. Surface Guard is closer to an operational EASM monitoring product.
- SecurityTrails — SecurityTrails provides current and historical internet asset data for domains, DNS records, WHOIS, IP addresses, subdomains, asset exposure signals, and related infrastructure. Its API documentation describes read-only access to IP, DNS, WHOIS, and company-related information, with JSON responses and REST endpoints. SecurityTrails is valuable when analysts need to reconstruct how infrastructure changed over time, find related domains, enrich alerts, investigate suspicious infrastructure, map exposed hostnames, or feed DNS and IP context into SIEM, SOAR, threat intelligence, or internal asset workflows. It is not automatically the full remediation, ownership, alert-routing, and verified monitoring workflow that an EASM team may need. SecurityTrails data can identify historical records, related infrastructure, open-port metadata, and exposure signals, but teams still need active validation before treating a candidate as an exploitable issue.
- SurfaceGuard — Surface Guard presents itself as an external attack surface management product that continuously scans external exposure, discovers new assets, identifies vulnerabilities, classifies risks, suggests mitigation actions, and sends alerts. Its public site lists StartUp, Business, and Custom plans, monitored-domain limits, weekly or daily reports, email alerts, Slack and Teams integrations, Integration API, SIEM integration on Custom, and Splunk or Wazuh positioning. Surface Guard’s strongest public signals are monitored-domain packaging, alerting, reporting, dashboards, AI-assisted risk classification, and subdomain takeover monitoring. Its weaker public signal is scanner-level transparency: buyers should verify exact scanner coverage, test methodology, false-positive handling, and evidence quality during a trial.
Head-to-head: SecurityTrails vs SurfaceGuard feature breakdown
The feature gap is about workflow, not only data.
SecurityTrails helps you know more about internet infrastructure. Surface Guard helps you monitor and act on external exposure.
| Feature | SecurityTrails | SurfaceGuard | Practical takeaway |
|---|---|---|---|
| Historical DNS | Core strength. SecurityTrails is widely used for current and historical DNS intelligence. | Not publicly positioned as a historical DNS intelligence platform. | Use SecurityTrails when DNS history is central to the investigation. |
| Current DNS records | Supported through web and API workflows. | Relevant through EASM discovery, but not publicly detailed as a DNS-intelligence product. | SecurityTrails is stronger for DNS record research and enrichment. |
| WHOIS and domain intelligence | Supported through current and historical domain and WHOIS-oriented data access. | Not publicly positioned as a WHOIS intelligence product. | SecurityTrails is stronger for attribution, historical ownership, and domain investigation. |
| Subdomain discovery | Strong for subdomain discovery and historical infrastructure research. | Public site says it monitors subdomains and identifies takeover exposure. | SecurityTrails is stronger for discovery data; Surface Guard is stronger for monitoring workflow. |
| Associated domains and related infrastructure | Useful for related-domain and infrastructure correlation, but buyers should verify associated-domain access, limits, and export or API availability for the selected plan. | Not publicly detailed as an associated-domain intelligence product. | SecurityTrails is stronger when related-infrastructure research is the goal. |
| IP intelligence | Supported through IP, DNS, WHOIS, company, and asset data access. | May detect exposed services as part of EASM, but public detail is limited. | SecurityTrails is stronger for enrichment; Surface Guard is stronger for monitored exposure handling. |
| Open ports and services | SecurityTrails asset APIs include open-port filters and additional asset fields in current docs. | Public site mentions exposed services in examples, but scanner-level port coverage is not publicly detailed. | Verify port coverage, freshness, and scan cadence in both tools if exposed-service detection is a core requirement. |
| Active surface monitoring | Can support monitoring through projects, API, saved workflows, and integrations, but its core public identity is data intelligence. | Public site describes 24/7 scanning and automatic asset discovery. | Surface Guard is more directly packaged for monitoring. |
| Risk classification | SecurityTrails asset APIs include exposure score and exposure severity fields in current docs. | Public site highlights AI classification, priority ranking, and mitigation suggestions. | Surface Guard markets risk workflow more directly; SecurityTrails exposes useful risk signals for data-driven teams. |
| Subdomain takeover | Can help discover dangling DNS and historical context, but takeover validation workflow must be built around it. | Public site explicitly highlights subdomain takeover monitoring and remediation guidance. | Surface Guard is more directly positioned for takeover monitoring. |
| Reports | Reporting depends on product plan, exports, API use, or internal tooling. | StartUp lists weekly reports; Business lists daily reports and compliance reports; Custom lists custom reports. | Surface Guard has clearer public report cadence. |
| Alerts | API and enrichment workflows can support alerting through internal tools. | Public site lists email alerts, real-time alerts on Business, Slack, Teams, Discord, and SIEM paths. | Surface Guard is easier to evaluate for operational alerting. |
| Integrations | SecurityTrails API is suited to SIEM, security automation, threat intelligence, and internal enrichment workflows. | Surface Guard publicly references Slack, Teams, Discord, Splunk, Wazuh, Integration API, and SIEM integration. | SecurityTrails is better for data integration; Surface Guard is better for ready-made alert destinations. |
| Documentation depth | Strong API documentation for data access and asset query workflows. | Public product page is useful, but scanner-level documentation is lighter. | SecurityTrails is easier to validate technically from public docs. |
Coverage comparison
Coverage should be judged against the job each product is built to do.
SecurityTrails coverage is strongest when the question is historical or passive: what records existed, what domains are related, which hostnames appeared, and how infrastructure changed.
Surface Guard coverage is strongest when the question is operational: what monitored domains are exposed, which risks need attention, where should alerts go, and what should the team fix.
| Coverage area | SecurityTrails | SurfaceGuard |
|---|---|---|
| Historical DNS | Strong fit | Not the main public positioning |
| Passive DNS-style investigation | Strong fit | Not the main public positioning |
| WHOIS and domain context | Strong fit | Not publicly detailed |
| Subdomain discovery | Strong fit for discovery and enrichment | Strong fit for monitored-domain subdomain exposure |
| Associated-domain and infrastructure correlation | Useful for related-domain and infrastructure research; plan-level access should be verified | Not publicly detailed |
| Open-port filters and infrastructure enrichment | Supported in current asset API documentation | Public examples mention exposed services, but scanner-level coverage should be verified |
| Continuous monitored-domain workflow | Possible through implementation and product workflows, but not the clearest public packaging | Core public positioning |
| Operational alerts | Usually built through API or internal tooling | Publicly listed through email, chat, and integration channels |
| Compliance-style reports | Not the clearest public positioning | Business plan publicly lists compliance reports for ISO 27001, LGPD, PCI DSS and others |
| Remediation guidance | Data must usually be translated into remediation by analysts or internal tools | Public site says it suggests mitigation actions and priority steps |
Passive DNS intelligence vs active surface monitoring
Passive DNS intelligence and active surface monitoring solve different problems.
Passive DNS intelligence is best when you need historical context. It helps answer questions such as: where did this domain point last month, what subdomains existed before, what infrastructure is related, and what records changed over time?
Active surface monitoring is best when you need operational action. It helps answer questions such as: what is exposed now, which monitored domain changed, which risk should be fixed first, and which team should be alerted?
Most mature external security programs need both. Passive intelligence improves discovery and investigation. Active monitoring turns exposure into recurring security work.
| Need | Passive DNS intelligence | Active surface monitoring |
|---|---|---|
| Investigate historical infrastructure | Strong | Limited unless historical scan data is retained |
| Find related domains and old hostnames | Strong | Useful if discovery sources include those assets |
| Understand DNS drift over time | Strong | Strong if recurring scans compare history |
| Alert when a new risky asset appears | Requires API or internal alerting workflow | Core monitoring use case |
| Route a finding to an owner | Requires internal workflow | More directly supported by EASM-style operations |
| Generate remediation guidance | Analyst or internal tooling usually translates the data | Public Surface Guard materials emphasize mitigation suggestions |
| Support threat hunting | Strong | Useful, but not the primary workflow |
| Support executive or compliance reporting | Possible through exports or custom reports | More directly packaged in Surface Guard’s public plan table |
Who should use which tool
The right choice depends on whether your team needs intelligence data, monitoring workflow, or both.
SecurityTrails is usually stronger for analysts and engineers who want reliable DNS and internet-infrastructure context. Surface Guard is usually stronger for teams that want EASM-style monitoring, alerting, and reporting without building the workflow themselves.
| Buyer need | Better fit | Why |
|---|---|---|
| Historical DNS investigation | SecurityTrails | Its core value is current and historical DNS, domain, WHOIS, and IP intelligence. |
| Subdomain discovery for OSINT | SecurityTrails | SecurityTrails is well-suited for finding and enriching domain infrastructure. |
| Monitored-domain EASM workflow | SurfaceGuard | Surface Guard publicly packages monitored domains, reports, alerts, dashboards, and integrations. |
| Subdomain takeover monitoring | SurfaceGuard | Surface Guard explicitly highlights subdomain takeover monitoring and remediation instructions. |
| SIEM or automation enrichment | SecurityTrails | The read-only API is built for integrating IP, DNS, WHOIS, and company data into security automation workflows. |
| Chat-based alert routing | SurfaceGuard | Surface Guard publicly lists Teams, Slack, Discord, email, and SIEM-oriented integrations. |
| Threat hunting and infrastructure correlation | SecurityTrails | Historical DNS, WHOIS, IP context, and related-infrastructure data help analysts connect infrastructure. |
| Compliance-style reports | SurfaceGuard | Business plan publicly lists compliance reports for ISO 27001, LGPD, PCI DSS and others. |
| Building an internal ASM platform | SecurityTrails | SecurityTrails can act as a data source for internal inventory, enrichment, and investigation pipelines. |
| Buying an off-the-shelf EASM monitoring workflow | SurfaceGuard | Surface Guard is more directly positioned as a ready-made monitoring and alerting product. |
Pricing comparison
Pricing is not directly comparable because SecurityTrails prices data access and intelligence workflows, while Surface Guard prices monitored-domain EASM workflow.
SecurityTrails’ public pricing page currently lists Professional at $500/month, Business at $1,500/month, and Enterprise as contact sales. Buyers should verify the current plan table, query limits, API access, historical data access, commercial-use rights, and contract terms directly with SecurityTrails before procurement.
Surface Guard’s public plan table lists prices in U.S. dollars, while other page copy includes Brazil-focused cost examples in reais, so buyers should verify currency, taxes, billing terms, contract scope, and procurement details directly with the vendor.
Do not compare only the monthly number. Compare how each tool will be used: data enrichment, analyst investigation, alerting, reporting, monitored domains, API limits, integrations, remediation workflow, and ownership routing.
| Vendor | Plan or model | Publicly listed scope | What to verify |
|---|---|---|---|
| SecurityTrails | Professional — $500/month | Public pricing page lists Professional with 20,000 queries/month | Current price, exact query limit, API endpoints, historical data access, commercial-use rights, exports, and overage terms |
| SecurityTrails | Business — $1,500/month | Public pricing page lists Business with 65,000 queries/month | Current price, query volume, team access, associated-domain features, historical WHOIS/DNS access, API limits, and licensing |
| SecurityTrails | Enterprise — contact sales | Custom enterprise API pricing and packaging | Data rights, bulk access, SLA, support, custom limits, commercial usage, internal redistribution, and contract terms |
| SurfaceGuard | StartUp — $199/month | Up to 3 monitored domains, weekly reports, email alerts, chat support, basic dashboard | Currency, taxes, billing terms, scanner list, domain definition, report format, alert payloads, and evidence quality |
| SurfaceGuard | Business — $459/month | Up to 20 monitored domains, daily reports, compliance reports, real-time alerts, Slack/Teams integrations, advanced dashboard, Integration API, priority support | Currency, taxes, compliance report scope, API limits, Slack/Teams setup, scanner coverage, and false-positive handling |
| SurfaceGuard | Custom — on request | Unlimited domains, custom reports, custom integrations, SIEM integration, dedicated support, custom SLA, team training | SLA wording, SIEM data format, Splunk/Wazuh behavior, onboarding, contract scope, support level, and custom integrations |
Questions to ask during a trial or demo
Do not evaluate SecurityTrails and Surface Guard using the same checklist only.
For SecurityTrails, test data quality, API fit, historical depth, query limits, licensing, and enrichment workflow. For Surface Guard, test scanner coverage, alert quality, reports, remediation guidance, integrations, and monitored-domain behavior.
For Surface Guard, ask for a scanner-by-scanner sample report showing the exact evidence collected for DNS, subdomain takeover, exposed services, web headers, TLS, cloud exposure, sensitive files, alert routing, and remediation instructions.
- What exactly is in scope? — Ask whether domains, subdomains, IPs, CNAMEs, associated domains, DNS records, projects, monitored domains, and discovered assets are counted separately.
- How fresh is the data? — For SecurityTrails, verify update cadence and historical coverage. For Surface Guard, verify scan cadence, alert latency, and report cadence.
- What evidence appears in a finding? — A useful result should include asset, timestamp, source, evidence, risk explanation, and next action.
- Can the result become an engineering task? — Surface monitoring should produce owner-actionable findings. Data intelligence may need internal ticketing or automation.
- How are false positives handled? — Ask whether findings can be validated, suppressed, tagged, assigned, exported, or rechecked.
- What does a clean result mean? — Ask how each vendor exposes missing data, unavailable sources, API failures, scan gaps, excluded assets, and rate limits.
- How does pricing scale? — For SecurityTrails, ask about queries, endpoints, users, commercial-use rights, and overages. For Surface Guard, ask about monitored domains, custom integrations, API use, reports, and alert destinations.
- Which integrations are included? — Do not assume Slack, Teams, Discord, Splunk, Wazuh, SIEM, API, or export access is included at the tier you plan to buy.
Where ExternalSight fits if you are comparing both
If the reason you are comparing SecurityTrails and Surface Guard is external attack surface monitoring, ExternalSight should also be evaluated as a domain-focused EASM workflow.
ExternalSight is built for internet-facing domains and combines on-demand asynchronous scans, continuous monitoring for verified domains, issue classification, remediation planning, historical comparison, alerting, PDF export, JSON export on supported plans, and plan-gated notifications and webhooks.
Its scanner workflow covers DNS, certificate transparency, subdomains, technology detection, SSL/TLS, HTTP headers, TLS configuration, subdomain takeover, subdomain HTTPS, API discovery, JavaScript endpoints, cookie security, CORS, mixed content, redirects, credentials, secrets, phishing, ports, cloud exposure, email spoofing, zone transfer, admin panels, HTTP configuration, infrastructure, login surface, sensitive files, open redirects, host header issues, GraphQL, exposed services, Firebase, Wayback, supply chain, asset discovery, IP intelligence, WAF, robots.txt, security.txt, sitemap, reputation, WHOIS, CSP, Shodan, passive DNS, OTX, and attack-chain evaluation.
ExternalSight also tracks scan coverage and unavailable scanners. Some external-source checks may report unavailable when API keys or upstream services are not configured. Review scan coverage before treating a clean scan as a clean surface.
ExternalSight does not replace SecurityTrails as a historical DNS intelligence database, Surface Guard’s commercial offering, a SIEM, a SOC, a WAF, a penetration test, or a cloud security platform. Its role is to turn verified-domain exposure into classified, monitored, exportable, owner-actionable security work.
Final verdict
Choose SecurityTrails if your primary need is passive DNS intelligence, historical DNS, WHOIS, IP context, subdomain discovery, related-infrastructure research, or API enrichment for security tools.
Choose Surface Guard if your primary need is active surface monitoring across monitored domains with alerts, reports, dashboards, integrations, AI-assisted risk classification, and subdomain takeover monitoring.
The practical buying rule is simple: SecurityTrails is better as an intelligence source; Surface Guard is better as an external monitoring workflow.
For mature teams, the two can complement each other. SecurityTrails can enrich discovery and investigation, while an EASM workflow turns external exposure into owner-assigned remediation and recurring monitoring.
Frequently asked questions
- SecurityTrails vs SurfaceGuard: which is better?
- SecurityTrails is better for passive DNS intelligence, historical DNS, WHOIS, IP context, subdomain discovery, related-infrastructure research, and API enrichment. Surface Guard is better for monitored-domain external attack surface monitoring with alerts, reports, dashboards, integrations, and remediation-oriented workflow.
- Is SecurityTrails an EASM platform?
- SecurityTrails can support attack surface intelligence and asset discovery workflows, especially through DNS, WHOIS, IP, associated-infrastructure, exposure, and API data. However, buyers should not treat internet asset intelligence alone as a complete EASM remediation and monitoring program.
- Is SurfaceGuard better for active monitoring?
- Surface Guard is more directly positioned as an active external surface monitoring product. Its public site describes 24/7 scanning, automatic asset discovery, monitored-domain limits, reports, real-time alerts, integrations, dashboards, and subdomain takeover monitoring.
- Can SecurityTrails and SurfaceGuard be used together?
- Yes. SecurityTrails can enrich discovery and investigation with DNS, WHOIS, IP, asset, and historical context. Surface Guard can monitor selected domains and route findings through reports, alerts, dashboards, and integrations.
- Which tool has clearer public pricing?
- Surface Guard lists StartUp at $199/month, Business at $459/month, and Custom on request. SecurityTrails lists Professional at $500/month, Business at $1,500/month, and Enterprise contact sales. Buyers should verify current pricing, currency, taxes, licensing, limits, and contract details directly with each vendor.
References and further reading
- SecurityTrails official website — https://securitytrails.com/
- SecurityTrails pricing — https://securitytrails.com/corp/pricing
- SecurityTrails API overview — https://docs.securitytrails.com/docs/overview
- SecurityTrails API — Find Assets — https://docs.securitytrails.com/reference/assets-find_assets-1
- SecurityTrails API and integrations — https://securitytrails.com/corp/integrations
- SecurityTrails stats — https://securitytrails.com/stats
- Recorded Future — SecurityTrails — https://support.recordedfuture.com/hc/en-us/articles/360053545614-SecurityTrails
- Surface Guard official website and pricing — https://surfaceguard.net/
Turn DNS intelligence into monitored external exposure work
ExternalSight helps teams scan internet-facing domains, classify external findings, generate remediation plans, compare scan history, receive alerts, export reports, review scan coverage, and monitor verified domains on supported plans. Use it when passive discovery needs to become owner-assigned external attack surface work.