You have a website in production. Maybe it is a SaaS app, an e-commerce store, or a side project you launched last month. You think it is secure, but you have never actually tested it. A free website security scan takes less than 60 seconds and can surface vulnerabilities that an attacker would find in minutes.
This guide explains what a security scan actually checks, how to interpret the results, and what you should fix first.
How to Run a Free Security Scan with CheckVibe
Running your first scan takes three steps and under 60 seconds.
Step 1: Enter your URL. Go to CheckVibe, create a free account, and enter your website URL. The scanner accepts any publicly accessible URL, including subdomains, specific paths, and single-page applications. You do not need to install anything or add code to your site.
Step 2: Wait for the scan to complete. CheckVibe crawls your site to discover pages and endpoints, then runs 100+ security checks against every discovered URL. The scan typically finishes in 30 to 60 seconds. You will see a progress indicator showing which check categories are running.
Step 3: Review your results. The scan produces a prioritized report grouped by severity. Each finding includes a description of the vulnerability, the specific URL or endpoint where it was found, the potential impact, and step-by-step fix guidance. Start at the top (critical findings) and work your way down.
What Does a Website Security Scan Check?
A comprehensive security scan tests your site against dozens of known vulnerability categories. Here is what each category covers and why it matters.
SSL/TLS Configuration
Your SSL certificate encrypts traffic between your users and your server. A scan checks:
- Whether the certificate is valid and not expired
- Which TLS protocol versions your server supports (TLS 1.2+ is required; anything older is vulnerable)
- Whether the cipher suites are strong enough to resist attacks
- Whether HSTS headers force browsers to always use HTTPS
A failing SSL check means user data, including passwords and payment information, could be intercepted in transit.
Security Headers
Security headers are HTTP response headers that tell browsers how to handle your content. A scan checks for:
- Content-Security-Policy (CSP) -- controls which scripts, styles, and resources can load on your pages. Without it, cross-site scripting attacks are trivially easy.
- X-Frame-Options -- prevents your site from being embedded in iframes on malicious sites (clickjacking).
- X-Content-Type-Options -- stops browsers from MIME-sniffing responses, which can turn a harmless file into an executable script.
- Referrer-Policy -- controls how much URL information leaks to third-party sites.
- Strict-Transport-Security (HSTS) -- ensures browsers always use HTTPS, even if a user types
http://. - Permissions-Policy -- restricts access to browser APIs like camera, microphone, and geolocation.
Most web frameworks do not set these headers by default. If you have never configured them, you are almost certainly missing several.
Cross-Site Scripting (XSS)
XSS vulnerabilities let attackers inject malicious JavaScript into your pages. A scan probes your endpoints with common XSS payloads and checks whether they are reflected or stored without sanitization.
The impact ranges from session theft (stealing a user's login cookies) to full account takeover (changing passwords, exfiltrating data).
SQL Injection
SQL injection occurs when user input is inserted directly into database queries. A scan tests your forms, search fields, and API parameters for injectable patterns, including error-based, time-based blind, and boolean-based blind injection.
A single SQL injection vulnerability can give an attacker read and write access to your entire database.
Exposed API Keys and Secrets
One of the most common issues on modern web apps is API keys visible in client-side JavaScript. A scan checks your page source, JavaScript bundles, and network responses for:
- AWS access keys
- Stripe secret keys
- Supabase service role keys
- Firebase admin credentials
- Database connection strings
- JWT signing secrets
- Keys from dozens of other providers
A leaked API key can result in unauthorized charges, data breaches, or complete infrastructure compromise, depending on the service.
CORS Misconfiguration
Cross-Origin Resource Sharing (CORS) headers control which domains can make requests to your API. A scan tests for:
- Wildcard
*origins on authenticated endpoints - Origin header reflection without an allowlist
- Null origin acceptance
- Overly permissive method lists
A misconfigured CORS policy lets any website make authenticated requests to your API on behalf of your users.
CSRF Protection
Cross-Site Request Forgery attacks trick a user's browser into making unwanted requests to your app while they are logged in. A scan checks whether your state-changing endpoints (POST, PUT, DELETE) validate the request origin or use CSRF tokens.
Cookie Security
Cookies that store session tokens need specific flags to be secure. A scan checks for:
- Secure flag -- ensures cookies are only sent over HTTPS
- HttpOnly flag -- prevents JavaScript from reading the cookie (mitigates XSS-based session theft)
- SameSite attribute -- prevents the cookie from being sent in cross-origin requests
DNS Configuration
DNS misconfigurations can enable email spoofing, domain hijacking, and man-in-the-middle attacks. A scan checks:
- SPF records -- which servers are authorized to send email for your domain
- DKIM records -- email authentication signatures
- DMARC policy -- what happens when SPF/DKIM checks fail
- DNSSEC -- whether DNS responses are cryptographically signed
Dependency Vulnerabilities
Modern web apps pull in hundreds of npm packages. A scan checks your visible dependencies against known CVE databases to flag packages with published security vulnerabilities.
Backend-Specific Checks
If your app uses Supabase, Firebase, Vercel, Netlify, or other platforms, a scan tests for platform-specific misconfigurations:
- Supabase tables with Row Level Security disabled
- Firebase security rules in test mode
- Exposed admin dashboards
- Default configurations that should have been changed
How to Read Your Scan Results
Findings are categorized by severity. Here is what each level means with a concrete example of what you might see.
Critical
Actively exploitable vulnerabilities that could lead to data breaches. Fix these immediately.
Example finding: "Supabase service_role key exposed in client-side JavaScript bundle at /static/js/main.abc123.js. This key bypasses all Row Level Security policies and grants full read/write access to your database."
High
Serious issues that significantly increase your attack surface. Fix these before launch.
Example finding: "CORS policy reflects any Origin header on /api/users endpoint. An attacker-controlled website can make authenticated requests to this API and read the response, accessing user data."
Medium
Issues that weaken your security posture. Plan to fix these soon.
Example finding: "Session cookie 'auth-token' is missing the HttpOnly flag. If a cross-site scripting vulnerability exists elsewhere in the application, an attacker could steal session tokens via JavaScript."
Low
Best practice recommendations and minor improvements. Address these when you can.
Example finding: "Permissions-Policy header is not set. While not directly exploitable, adding this header prevents your site from being used to request camera, microphone, or geolocation access by injected scripts."
Start with critical findings and work your way down. Each finding should come with a description of the vulnerability, its impact, and specific guidance on how to fix it.
What Free Scans Do Not Catch
A free external scan is powerful, but it has limitations. Understanding these boundaries helps you make informed decisions about your security strategy.
Authenticated flows. A free scan tests your site as an unauthenticated visitor. It cannot log in, navigate your dashboard, or test endpoints that require a session. Vulnerabilities behind login walls, such as privilege escalation, insecure direct object references (IDOR), or broken access control between user roles, require authenticated scanning.
Server-side logic. External scans observe your app's HTTP responses. They cannot read your source code, inspect your database queries, or analyze your server-side business logic. A scan might detect that your error responses leak stack traces, but it cannot verify that your payment processing logic correctly validates amounts.
Rate-limited or WAF-protected endpoints. If your web application firewall (WAF) blocks the scanner's requests, those endpoints will not be tested. This is a trade-off: a WAF protects you from real attacks, but it can also prevent security scanners from finding issues behind it.
Zero-day vulnerabilities. Scanners test against known vulnerability patterns and signatures. A novel attack technique that has not been cataloged will not be detected until scanners are updated to look for it.
For deeper coverage, consider upgrading to a paid plan that includes site crawling with greater depth, scheduled recurring scans, and more scan volume per month.
Common False Positives and How to Handle Them
No scanner is perfect. Here are common false positives you may encounter and how to evaluate them.
CSP violations on CDN resources. If you load scripts from a well-known CDN like cdnjs.cloudflare.com, a strict CSP audit may flag it. Verify the CDN is legitimate and add it to your CSP script-src directive.
CORS findings on public APIs. If your endpoint is genuinely a public API with no authentication (like a status page or public data feed), Access-Control-Allow-Origin: * is correct. Mark the finding as dismissed with a note explaining why.
Cookie flags on third-party cookies. Scanners sometimes flag cookies set by third-party services (analytics, chat widgets) that you do not control. Focus on cookies your application sets directly.
SSL warnings on development subdomains. If a scan detects an SSL issue on staging.yourdomain.com, that is still worth fixing, but prioritize your production domain first.
When you encounter a potential false positive, verify it manually before dismissing it. The finding is more likely real than not.
CheckVibe Free Scan vs Other Free Scanners
Several free tools test individual aspects of website security. Here is how they compare.
| Tool | Scope | Checks | Crawling | Fix Guidance | |------|-------|--------|----------|-------------| | CheckVibe Free | Full-stack (SSL, headers, XSS, SQLi, API keys, CORS, cookies, DNS, deps, BaaS) | 100+ | Yes, discovers pages and endpoints | Yes, per-finding | | SSL Labs | SSL/TLS only | Deep SSL analysis | No | Limited | | SecurityHeaders.com | HTTP headers only | 6-8 headers | No (single URL) | Basic | | Mozilla Observatory | Headers + TLS + best practices | ~15 checks | No (single URL) | Yes |
SSL Labs is the gold standard for SSL/TLS testing. It provides deeper cipher suite analysis than most general scanners. However, it only tests SSL, nothing else.
SecurityHeaders.com gives you a quick letter grade for your HTTP security headers. It is fast and useful for a single check, but it does not test for application-level vulnerabilities like XSS, SQL injection, or leaked API keys.
Mozilla Observatory combines header checks with some TLS and best-practice tests. It covers more ground than SecurityHeaders.com but still does not crawl your site or test for injection vulnerabilities.
CheckVibe runs all of the above plus application-level security testing: XSS, SQL injection, API key detection, CORS auditing, CSRF checks, cookie security, DNS configuration, dependency scanning, and backend-specific checks for Supabase, Firebase, Vercel, and more. It also crawls your site to discover pages and endpoints, rather than testing a single URL in isolation.
For the most thorough free assessment, run CheckVibe for the full picture, then use SSL Labs if you want a deeper dive into your TLS configuration specifically.
Why Free Scans Matter
The barrier to entry for attackers is zero. Automated bots continuously scan every public website for known vulnerabilities. They do not care whether your site gets 10 visitors or 10 million.
A free scan puts you on equal footing. You see the same attack surface that automated tools would find, and you get a chance to fix it first. The best time to scan is before your users discover the problem, or worse, before an attacker does.
How Often Should You Scan?
Once is not enough. Your site changes with every deployment, and new vulnerabilities are discovered in dependencies constantly. Aim for:
- After every deployment to catch issues introduced by new code
- Weekly at minimum to catch newly disclosed dependency CVEs
- Immediately after any infrastructure change (DNS, hosting, SSL)
If you want automated recurring scans, CheckVibe's paid plans include scheduled daily, weekly, or monthly scans with alert rules that notify you when your security score drops or new critical findings appear.
FAQ
Is a free security scan accurate?
Yes. A free scan uses the same detection engine as paid tiers. The checks are identical. What differs is volume (how many scans per month), crawling depth (how many pages the scanner discovers), and access to features like PDF export and scheduled monitoring. The findings themselves are equally accurate on the free tier.
Can a free scan find all vulnerabilities?
No single scan, free or paid, finds every vulnerability. A free external scan covers a wide range of common issues: SSL misconfigurations, missing headers, injection vulnerabilities, exposed secrets, CORS problems, and more. However, it cannot test authenticated flows, analyze your source code, or detect business logic flaws. Think of a free scan as a strong first line of defense that catches the most common and most exploitable issues. For deeper coverage, combine automated scanning with manual security review.
Is it safe to scan my website?
Yes. CheckVibe's scanner sends standard HTTP requests to your publicly accessible URLs. It does not attempt to exploit vulnerabilities, modify data, or perform destructive actions. The scan behaves like a well-intentioned visitor browsing your site, with additional checks on the HTTP responses it receives. It will not trigger data loss, downtime, or account lockouts.
How often should I run a free scan?
At minimum, scan after every deployment and once a week. Deployments can introduce new vulnerabilities through code changes, and new CVEs are published in dependency databases daily. If your site handles sensitive data (authentication, payments, personal information), weekly scanning is the baseline. Many teams run daily scans through CheckVibe's monitoring feature to catch regressions as soon as they happen.
What should I do after my first scan?
Start with critical findings and fix them immediately. These are the vulnerabilities most likely to be exploited. Then work through high-severity issues before your next deployment. For medium and low findings, create tickets and address them in your normal development cycle. After fixing issues, run another scan to confirm the fixes are in place. For a structured approach to prioritizing fixes, see our guide on what to look for in a website security assessment.
Scan Your App Now
CheckVibe offers a free website security scan that runs 100+ checks in under 60 seconds. Enter your URL, get a full security report with severity ratings and fix guidance, and start closing vulnerabilities today.
No configuration required. No code to install. Run your free scan now.
Want to understand the full landscape of security scanning tools? Read our website security scanner comparison. New to security scanning? Start with what is website security scanning.