Cookie Security Checker | Vulnify Free Security Tool
Free online cookie security checker — review Secure, HttpOnly, and SameSite flags on login and session cookies. Paste a URL, run Quick Check, and get actionable hardening guidance with no signup.
What This Tool Checks
- Cookie inventory evidence
- Secure/HttpOnly/SameSite gaps
- Session hardening playbook
Why It Matters
Session and authentication weaknesses often show up in cookie flags long before they appear in breach reports. Missing Secure, HttpOnly, or SameSite protections can quietly weaken otherwise solid applications.
Best For
Best for teams reviewing sign-in flows, session handling, embedded experiences, checkout state, or recent changes to auth and application middleware.
What To Do Next
Use the findings to prioritize session-cookie fixes first, then verify whether your cross-site flows, logout behavior, and browser compatibility still work as intended.
Related Resources
Frequently Asked Questions
What does the Cookie Security Checker test?
The Cookie Security Checker fetches your URL and inventories Set-Cookie headers on the response. It flags missing Secure, HttpOnly, and SameSite protections, highlights risky SameSite=None combinations, and surfaces session cookies that may be exposed to script or cross-site abuse.
Is this cookie security checker free?
Yes. Quick Check is free with no account required. Paste a public HTTPS URL you are authorized to test, submit, and review cookie flag findings in seconds.
How do I check cookie security on my website?
Enter the login page, checkout flow, or any URL that sets session cookies. Run Quick Check to see each cookie name, flag status, and recommended fixes. Retest after deploying Set-Cookie changes to confirm Secure, HttpOnly, and SameSite behave as intended in production.
What are HttpOnly, Secure, and SameSite?
HttpOnly blocks JavaScript from reading the cookie — critical for session tokens when XSS is a risk. Secure limits the cookie to HTTPS connections. SameSite controls whether the browser sends the cookie on cross-site requests: Lax or Strict reduces CSRF risk; None requires Secure and is only appropriate for genuine cross-site flows like embedded payments or SSO.
How is a cookie checker different from a website security checker?
A cookie security checker focuses on session hardening — the Set-Cookie flags that protect authentication state. A broader website security checker tests injection flaws, exposed paths, TLS, headers, and other OWASP-aligned risks across your site. Use both: harden cookies first, then run a full vulnerability scan for defense in depth.
When should I run a cookie security check?
Run a check after auth changes, framework upgrades, CDN or reverse-proxy moves, payment or SSO integrations, and before launch sign-off. Cookie misconfigurations often survive QA because flows work in the browser even when flags are weak.
Can I test login and checkout URLs?
Yes, as long as you own the site or have permission to test it. Point the checker at the public URL that issues Set-Cookie headers — typically your sign-in, registration, or checkout entry point — and review the flags on each authentication cookie.
How do I fix insecure cookie flags?
Start with session and authentication cookies: enable Secure and HttpOnly, then choose SameSite based on your real user journey (Lax for most logins, None only when cross-site behavior is required). See the insecure cookie flags fix guide for stack-specific Set-Cookie examples and retest with this checker.