S4E offers three plans: Free, Pro, and Enterprise. Current public pricing is always on s4e.io/plans.
Free shows you what is wrong now. Pro protects you when things change. Enterprise is for teams with multiple assets, internal infrastructure, or custom deployment needs.
Free
A no-cost plan for occasional checks and testing S4E. No credit card required.
Pricing: $0 — free forever.
What's included:
- 1 asset — one domain, subdomain, or IP address.
- Manual scans on demand — you start scans yourself.
- 11,000+ security checks — relevant checks based on the technologies and surfaces detected on your asset.
- Basic security reports
- Limited scan history
Limits: Daily and monthly scan limits apply. Alerts, dark web monitoring, and continuous monitoring are not included.
Getting started:
- Register at app.s4e.io/register.
- Add and verify your asset.
- Run a manual scan.
Pro
A self-serve plan for continuous protection of one critical internet-facing asset. Built for small businesses, SaaS companies, website owners, and small IT teams that need security without building a security team.
Pricing:
| Amount | |
|---|---|
| List price | $199 / month |
| Pro price | $119 / month (save 40%) |
| Billed | $1,428 / year (annual billing) |
| Trial | 14 days of full Pro access — no credit card required |
Pro costs less than $4 per day.
What's included:
- 1 continuously protected asset
- 24/7 change-aware monitoring — when a page, service, technology, DNS record, or exposed surface changes, S4E re-scans the affected area.
- 11,000+ continuously updated checks — including web and network vulnerability scanning.
- New CVE matching — newly published vulnerabilities are matched against technologies detected on your asset.
- Instant email alerts — new vulnerabilities, leaked credentials, or critical changes.
- AI fix recommendations — plain-language remediation steps for every finding.
- Dark web and credential leak monitoring
- Full scan history and weekly risk summary
- No agents or installations
- Email support
Scan limits: Fair use applies. Manual scans are capped at a few per hour. S4E monitors the asset automatically — you do not need to run scans yourself.
Getting started:
- Start a 14-day Pro trial at app.s4e.io/register.
- Add your domain, subdomain, or IP address.
- S4E maps the asset, starts monitoring, and sends alerts when something important changes.
Setup takes less than two minutes. No agent, plugin, or server access is required.
At the end of the trial you can subscribe to Pro or continue on Free — the asset stays in your account either way.
Free vs Pro
| Free | Pro | |
|---|---|---|
| Scanning | One-time snapshot | Continuous monitoring |
| Scan type | Manual | Automatic, change-aware |
| Security checks | 11,000+ checks | 11,000+ continuously updated |
| Scan limits | Daily and monthly limits apply | Fair use — manual scans capped at a few per hour |
| Reports | Basic reports | Prioritized findings and remediation |
| Who runs scans | You, manually | S4E monitors automatically |
| Alerts | — | Instant vulnerability alerts |
| Scan history | Limited | Full history |
| Fix guidance | Basic findings | AI-powered fix recommendations |
| Dark web | — | Credential leak and dark web monitoring |
| Best for | Testing S4E | Ongoing protection |
Note
S4E does not run every check against your asset on every scan. It selects relevant checks based on the technologies, services, configuration, and exposed surfaces it detects. Coverage grows as the asset grows.
Enterprise
A custom plan for organizations with multiple assets, complex infrastructure, MSSP / partner needs, or regulated environments.
Pricing: Custom — scoped to your needs. Contact [email protected].
What's included:
| Capability | Description |
|---|---|
| Multiple assets | Monitor domains, subdomains, IP addresses, and IP ranges. Pricing scales with asset count. |
| Multi-user access | Team members, roles, and shared asset management. |
| Multi-tenant architecture | MSSP / partner support for managing multiple clients. |
| White-label reporting | Brand reports with your own logos and company information. |
| Internal network scanning | Scan assets behind your firewall with an Enterprise connector. External scanning still requires no installation. |
| Compliance reporting | PCI-DSS, ISO 27001, and other framework reporting. |
| API and webhooks | Full REST API access for automation and integration. Additional alert channels (Slack, webhook, SMS) are available. |
| Custom dashboards | Tailored dashboards and reporting for your organization. |
| Dedicated account manager | Priority support with dedicated account management. |
Pro is designed for one critical internet-facing asset. For multiple assets or internal infrastructure, use Enterprise.
MSSP and partners: If you manage security for multiple clients, S4E can be the scanning, monitoring, reporting, and automation engine behind your managed service. See the Partner Program.
How continuous monitoring works
Traditional scanners run when you schedule them. S4E Pro and Enterprise monitor the asset all the time.
- Add your asset — enter a domain, subdomain, or IP address.
- S4E maps and scans it — technologies, services, pages, and exposed attack surfaces are identified.
- S4E monitors changes — new pages, services, redirects, DNS records, and technologies trigger targeted scanning. A full scan is not run on every change.
- You receive actionable alerts — severity, impact, and remediation steps when something important changes.
S4E is continuous automated security monitoring and vulnerability detection. It does not replace a manual penetration test or compliance audit.
What counts as one asset?
One domain, subdomain, or IP address counts as one asset. Examples: example.com, api.example.com, and 1.2.3.4 are each counted separately.
Managing your plan
- Start Free or Pro: app.s4e.io/register. Pro trial: add
?plan=pro&trial=true. - Upgrade: Go to User Settings → My Products. Use Billing Portal (Stripe) to subscribe or change billing.
- Payment methods: Credit and debit cards via Stripe.
- Cancel: Cancel renewal from account settings or the Billing Portal. Access continues until the end of the paid billing period. No cancellation fees.
- Enterprise: Contact [email protected]. Onboarding is scoped to your environment.
- API rate limits: Vary by plan. Enterprise customers can request custom limits.
Retired packages
Expert and Elite are no longer offered to new customers. Existing subscribers can manage those packages from the Billing Portal. New customers should choose Free, Pro, or Enterprise.