Best Website Security Scanners 2026
Short answer. For a basic security check, use free online tools: Mozilla Observatory and SecurityHeaders.com grade your HTTP security headers on an A–F scale, enterno.io gives a combined report on headers, Content Security Policy, cookies and SSL, while OWASP ZAP handles deep vulnerability scanning. Start with headers and SSL/TLS проверку, then move to dynamic analysis.
What a website security scanner does
A security scanner automatically checks how well your site is protected against common attacks. Different tools cover different layers, so in practice they are combined. Broadly, they fall into three groups:
- Header analyzers — check whether HTTP security headers (HSTS, CSP, X-Frame-Options, etc.) are present and configured correctly.
- Vulnerability scanners (DAST) — simulate attacks against a running application to find XSS, SQL injection and exposed directories.
- All-in-one online checkers — gather a summary of headers, SSL/TLS, cookies and basic misconfigurations in a single report.
If you are just starting, work from simple to complex: first close the basics (headers, HTTPS, secure cookies), then run a heavier dynamic scan.
Important: an A grade on SecurityHeaders.com or Mozilla Observatory does not mean you are fully protected — it grades only your HTTP headers, not vulnerabilities in the application itself. A site with an A grade can still be vulnerable to SQL injection or XSS in its code.
You can inspect exactly what headers a server returns right from your terminal:
curl -I https://example.comThe -I flag requests response headers only (an HTTP HEAD request) — the output shows the status code and whether Strict-Transport-Security, Content-Security-Policy and other security headers are present, without downloading the page body.
Security scanner comparison
| Tool | Type | Cost | Headers | Vuln scan | Best for |
|---|---|---|---|---|---|
| Mozilla Observatory | Header analysis | Free | Yes (A–F grade) | No | Developers, quick audit |
| SecurityHeaders.com | Header analysis | Free | Yes (A–F grade) | No | Single-page check |
| enterno.io | All-in-one checker | Free (48+ tools) | Yes + CSP/CORS/cookie | Partial (info disclosure) | Site owners, monitoring |
| OWASP ZAP | DAST scanner | Open-source | Partial | Yes (deep) | Pentest, CI/CD |
| Qualys SSL Labs | SSL/TLS | Free | No | TLS only | Certificate checks |
How to choose a tool
Your choice depends on the task and your level of access to the infrastructure:
- You need a quick rating — Mozilla Observatory or SecurityHeaders.com give a letter grade for your headers in seconds.
- You need a summary report with no install — online checkers like enterno.io show headers, Content-Security-Policy, cookie flags (HttpOnly, Secure, SameSite) and SSL status in one view.
- You need to find code vulnerabilities — OWASP ZAP scans a running application and finds XSS, injection and insecure endpoints. See our guide on how to prevent XSS attacks.
- You need perimeter protection — to filter traffic, use a Web Application Firewall.
Where to start your security check
A practical order of actions for most sites:
- Check your HTTP security headers and get a letter grade — this closes a large share of basic risks. See the full security headers guide.
- Make sure all traffic runs over HTTPS and HSTS is configured.
- Verify cookies carry the Secure, HttpOnly and SameSite flags.
- Scan the site for signs of malicious code — see our website malware check.
- Set up continuous monitoring so you learn about changes. On the free enterno.io plan you get 10 monitors and alerts via Telegram, Slack, email and webhook.
enterno.io offers 48+ free tools, including a security-header grade, CSP/CORS/cookie analyzers, a REST API документацию and an MCP server for automation — an honest toolkit for regular checks that complements specialized scanners.
A single scan is a point-in-time snapshot. Real protection comes not from a one-off check but from continuous monitoring: set up automatic alerts for header changes, SSL certificate expiry and new issues so you find out about a regression before an attacker does.
FAQ
Which security scanner is best for a beginner?
Start with header analyzers (Mozilla Observatory, SecurityHeaders.com) or an all-in-one online checker like enterno.io — they need no installation and give a clear rating. OWASP ZAP is more powerful but requires configuration skills.
Are free tools enough?
For basic hygiene, yes. Free services cover headers, HTTPS, cookies and SSL. For a deep penetration test of a large application you also need a DAST scanner like OWASP ZAP and manual expertise.
How often should I scan my site?
At a minimum, after every release and configuration change. Ideally, set up continuous monitoring that alerts you when headers change, SSL is about to expire, or issues appear.
How does header analysis differ from a vulnerability scanner?
Header analysis inspects server response configuration (CSP, HSTS, etc.) without attacking the site. A vulnerability scanner (DAST) actively tests the application by sending real requests to find XSS, injection and other flaws.