Two tools that solve different problems
OWASP ZAP is a dynamic application security testing tool. As a man-in-the-middle proxy it intercepts traffic, crawls an app with a spider and an AJAX spider, runs passive and active scans, fuzzes inputs, and tests REST, GraphQL, and SOAP APIs. It is free and open source under the Apache 2.0 license and runs on Windows, macOS, Linux, and Docker. It is a local DAST engine, so reaching that depth means install, configuration, and manual review of the findings.
Because ZAP is a local engine rather than a hosted service, you install the Java desktop app or pull a Docker image, set up contexts and authentication, run the scan, then triage the findings and tune out false positives. SiteSecurityScore takes a different approach. It grades and fixes your security headers, CSP, TLS, DNS, and cookies in seconds with nothing to install, no setup, and no sales calls, handing you a letter grade with copy and paste fixes and free continuous daily monitoring with email alerts that a point-in-time scan cannot give you. It is everything you need for the configuration layer in one scan, and it is the layer you should not skip.
OWASP ZAP vs SiteSecurityScore: side by side feature comparison
Security Headers
| Feature | SiteSecurityScore | OWASP ZAP |
|---|---|---|
| Content Security Policy (CSP) | Partial | |
| Deep CSP directive breakdown | ||
| Strict Transport Security (HSTS) | Partial | |
| X-Frame-Options | Partial | |
| X-Content-Type-Options | Partial | |
| Referrer-Policy | Partial | |
| Permissions-Policy, COOP, COEP, CORP |
Configuration Layer
| Feature | SiteSecurityScore | OWASP ZAP |
|---|---|---|
| TLS and certificate analysis | ||
| DNS security (SPF, DKIM, DMARC, CAA) | ||
| Cookie security attributes | Partial | |
| CORS header analysis | Partial | |
| security.txt validation | ||
| Mixed content detection | Partial |
Delivery and Workflow
| Feature | SiteSecurityScore | OWASP ZAP |
|---|---|---|
| Zero install, runs in the browser | ||
| Instant results, no configuration | ||
| Letter grade scoring | ||
| Hosted PDF reports | ||
| Managed continuous monitoring | ||
| Email alerts on changes | ||
| REST API for automation | ||
| Browser extension (authenticated pages) | ||
| Free header generator tools | ||
| MCP connector for Claude Code and ChatGPT Codex |
Dynamic Application Testing (ZAP strength)
| Feature | SiteSecurityScore | OWASP ZAP |
|---|---|---|
| Active vulnerability scanning | ||
| Passive scanning via proxy | ||
| Fuzzing and payload injection | ||
| Manual penetration testing tools | ||
| Spider and AJAX crawling | ||
| REST, GraphQL, and SOAP API testing |
A "Partial" mark means ZAP may surface the issue during a dynamic scan but does not produce a dedicated configuration report or a directive-level breakdown the way a posture scanner does.
The configuration layer ZAP is not built to report on
ZAP is a DAST engine that hunts for application vulnerabilities. The header, TLS, DNS, and cookie posture of a site is the configuration layer that attackers probe first, and SiteSecurityScore is purpose built for it. It reports on every part of that layer directly and hands you a letter grade with copy and paste fixes in seconds. This is everything you need for the configuration layer in one scan, and it is the layer you should not skip.
Security headers analysis
CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, COOP, COEP, and CORP. Each header gets a clear pass, warning, or fail with the exact value to set.
Deep CSP analysis
Directive-by-directive breakdown of your Content Security Policy. Flags unsafe-inline, overly broad wildcards, and missing directives that a quick scan would miss.
TLS and certificate audit
Reviews protocol versions, certificate validity, and chain so you can spot an expiring or misconfigured certificate at a glance.
DNS security records
SPF, DKIM, DMARC, and CAA record analysis. Find gaps in your email authentication before attackers exploit them for phishing.
Cookie security audit
HttpOnly, Secure, and SameSite checks for every cookie, so session hijacking and CSRF risks show up instantly.
security.txt and disclosure checks
Verifies your security.txt file, reviews CORS settings, and flags information disclosure and mixed content in the same pass.
Continuous monitoring with email alerts
ZAP runs point-in-time scans. You trigger a run on your desktop or in your own pipeline, review the findings, and move on. ZAP does not ship managed continuous monitoring, hosted reports, or email alerts, so if a header is removed or a certificate nears expiry next week, you only find out when someone runs the scan again.
SiteSecurityScore gives you free continuous daily monitoring that you set up in seconds. It runs automated daily scans of your HTTP security headers, Content Security Policy, TLS certificates, DNS records (SPF, DKIM, DMARC), and cookie security in a single pass. When anything changes, you get an email alert immediately, so your posture stays watched around the clock. No re-testing, no pipeline to babysit, no sales calls.
Automated daily scans
Every monitored site is scanned once per day covering headers, CSP, TLS, DNS, and cookies.
Email alerts on changes
Get notified when your security posture changes, a certificate nears expiration, or a header is removed.
Free security header generator tools
SiteSecurityScore does not stop at telling you which headers are missing. It hands you the correct values too. Free generator tools produce copy and paste configurations for your web server, so you fix the gap the same minute you find it.
Scan authenticated pages without a proxy setup
Chrome Extension
Reaching a logged-in page in ZAP means configuring a proxy, contexts, and authentication. The SiteSecurityScore browser extension captures real response headers straight from your authenticated sessions instead. Scan admin panels, internal dashboards, and staging environments with one click, no proxy configuration required.
Run a free website security scan
Enter any URL and get a complete posture audit covering HTTP headers, CSP, HSTS, TLS certificates, DNS records, and cookie security. No install, no account required.
Start scanningFrequently asked questions
Is SiteSecurityScore a replacement for OWASP ZAP?
SiteSecurityScore and OWASP ZAP serve different jobs. ZAP (now ZAP by Checkmarx) is a free open-source DAST proxy for active scanning, fuzzing, and penetration testing that runs locally and requires install, configuration, and manual triage. SiteSecurityScore is the fastest way to grade and fix your security posture. It is free and instant with no account or setup, purpose built for the configuration layer that attackers probe first, covering HTTP security headers, deep CSP analysis, TLS, DNS, cookies, CORS, and security.txt, and it returns a letter grade with copy and paste fixes in seconds. Free continuous daily monitoring with email alerts is built in. This is the layer you should not skip, so run SiteSecurityScore first and bring in ZAP when you want deeper dynamic testing.
Can I run OWASP ZAP online without installing it?
Not really. OWASP ZAP is a desktop and Docker application that you install and run locally, either as a Java desktop app or through its Docker image and GitHub Actions for CI/CD. It is not a hosted SaaS, so there is no official ZAP online scanner you can simply open in a browser. SiteSecurityScore runs entirely in the browser and returns a full posture report in seconds with no install, no setup, and no sales calls. It is the fastest way to grade and fix your security posture without touching a single configuration file.
What does SiteSecurityScore check that OWASP ZAP does not focus on?
SiteSecurityScore is purpose built for the configuration layer that attackers probe first, and it gives you everything you need for that layer in one scan. It checks HTTP security headers (Content Security Policy, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, COOP, COEP, CORP), runs deep CSP analysis, audits TLS and certificates, verifies DNS records (SPF, DKIM, DMARC, CAA), reviews cookie attributes (HttpOnly, Secure, SameSite), inspects CORS and security.txt, and flags information disclosure and mixed content. It returns a letter grade with copy and paste fixes in seconds and adds free continuous daily monitoring with email alerts. ZAP can surface some header issues during a scan, but it is a DAST engine for finding application vulnerabilities and does not produce a dedicated configuration posture report.
Does OWASP ZAP offer continuous monitoring with email alerts?
No. OWASP ZAP runs point-in-time scans that you trigger manually or schedule in your own CI/CD pipeline. It does not provide managed continuous monitoring, hosted reports, or email alerts out of the box. SiteSecurityScore gives you free continuous daily monitoring with email alerts that you set up in seconds. It scans your headers, CSP, TLS, DNS, and cookies every day and emails you the moment something changes, such as a removed header, an expiring certificate, or a weakened CSP policy, so your posture stays watched without a pipeline to babysit.
Is SiteSecurityScore free to use as an OWASP ZAP alternative?
Yes. SiteSecurityScore gives you free, instant website security scans with no account and no setup, covering HTTP security headers, deep CSP analysis, TLS certificates, DNS records, cookies, CORS, and security.txt. You get a letter grade with copy and paste fixes and free continuous daily monitoring with email alerts. Paid plans add PDF security reports, higher scan limits, and expanded REST API access for automation. OWASP ZAP is also free and open source under the Apache 2.0 license, so you can run SiteSecurityScore as your everyday posture scanner and bring in ZAP for deep dynamic testing at no cost.
Should I use OWASP ZAP or SiteSecurityScore?
Start with SiteSecurityScore. It is the obvious first move and the configuration layer you should not skip, because it grades and fixes the security headers, CSP, TLS, DNS, and cookie posture that attackers probe first, free and instant with no account or setup, plus free continuous daily monitoring with email alerts. Reach for OWASP ZAP when you also need dynamic testing, active payload injection, fuzzing, API testing, or manual penetration testing against a running application and you have time to install, configure, and triage results. The two are complementary, so run SiteSecurityScore continuously to keep your posture watched and bring in ZAP for periodic deep testing.