Know your external attack surface. Manage it.
Perimeter continuously discovers and monitors everything your business exposes to the internet — assets, misconfigurations, email security gaps, and more. Start with a free scan.
What you'll discover
Perimeter is built to reveal the kinds of external exposure smaller businesses often miss until they become a problem.
Unknown assets
See subdomains and connected assets you may not know are publicly visible.
Configuration gaps
Spot missing email protections, weak website settings, and common hygiene issues.
Actionable visibility
Understand what matters first, then unlock the full picture behind signup.
See enough to care. Then unlock control.
The free scan is designed to show something real and useful straight away: a score, a few clear findings, and a sense of what else may be hiding beneath the surface.
• Plain-language summaries, not dense technical output
• One surprising insight to create momentum
• Full findings, explanations, and monitoring behind signup
More than a scan. A security management platform.
The free scan is your starting point. Behind it is a complete external attack surface management platform built for the teams responsible for keeping a business secure.
Asset discovery & inventory
Perimeter automatically discovers connected domains, subdomains, IP ranges, and services including assets you did not register yourself. Every confirmed asset lives in one organised inventory.
Findings management
Every security issue is tracked as a finding with severity, status, and history. Triage findings, assign them to team members, set due dates, and walk issues from Open to Closed with a full audit trail.
Continuous monitoring & alerts
Perimeter rescans your assets automatically and alerts you when something changes: a new subdomain appears, a certificate is about to expire, or a previously passing check starts failing.
Risk register & governance
Accept, track, and justify risks in a structured register. Governance controls let you set policies across your organisation and track compliance posture over time.
Branded reports
Generate professional PDF reports showing your exposure score, open findings, and remediation status. Share with management or use as evidence for compliance reviews.
Threat intelligence feeds
Stay informed on zero-days and vendor advisories relevant to your stack without leaving the platform. Check if your domain credentials have appeared in any known breach.
Built by a security specialist, a data engineer, and a developer.
We started Perimeter because the tools that give real external security visibility were built for enterprise budgets. Smaller businesses — which need it just as much — had nothing between guesswork and an enterprise contract.
We're a European team. Our infrastructure runs in the EU and we take data sovereignty seriously as a baseline, not a selling point.
More about usThe checks, severity logic, and remediation guidance are grounded in real hands-on security expertise — not generic checklists.
The platform processes large volumes of external internet signals quickly and reliably, turning raw data into structured findings.
Security tools fail when they're too complex to use. We've built Perimeter to be the kind of tool that gets opened regularly, not just in a crisis.
How it works
The experience is intentionally simple: surprise first, then clarity and control.
Enter your domain
Start with the domain your business already owns and controls.
We analyse public signals
Perimeter checks connected assets, email security, website settings, and HTTPS hygiene.
See what needs attention
Preview the key issues first, then unlock the full report and ongoing monitoring.
One plan. Everything included.
No tiers, no feature gating, no surprises. One domain, the full platform, continuous monitoring.
Run your free scan now
Start with one domain and see what your business may be exposing to the internet.