Cookies Analyzer
Analyze Set-Cookie headers online for free. Paste any cookie header to instantly decode and inspect all attributes - cookie name, value (truncated), domain, path, Expires/Max-Age, Secure, HttpOnly, SameSite, and more. Perfect for debugging HTTP responses, verifying cookie security settings, and understanding cookie behavior. All processing happens locally in your browser - no data is uploaded.
Paste one or more Set-Cookie headers (or just the cookie definitions) below to analyze their attributes. Each line is parsed as a separate cookie. All processing happens locally in your browser.
Paste Set-Cookie headers above to analyze cookie attributes
Click one of the example presets above to get started
Why Use Our Cookies Analyzer?
Instant Set-Cookie Parsing
Paste any Set-Cookie header and instantly get a structured breakdown of the cookie. Our cookies analyzer parses the name, value, and all attributes including Domain, Path, Expires, Max-Age, Secure, HttpOnly, SameSite, and Priority with clear labels.
Cookie Security Analysis
Each cookie is automatically checked for security best practices. The cookies analyzer flags missing Secure flags, missing HttpOnly flags, and SameSite=None without Secure - helping you identify vulnerable cookie configurations at a glance.
Batch Cookie Analysis
Analyze multiple Set-Cookie headers at once by pasting them on separate lines. The cookies analyzer parses each cookie independently, showing a full breakdown with attribute badges and security warnings for every entry in a clean card-based layout.
100% Local Processing
Your cookie data never leaves your device. Everything is processed locally in your browser using pure JavaScript - no server uploads, no data logging, no API calls. Perfect for analyzing production session cookies and authentication tokens safely.
Common Use Cases for Cookies Analyzer
Debugging API Cookie Responses
When an API sets cookies with unexpected behavior, paste the Set-Cookie headers into the cookies analyzer to see exactly what attributes were set. Verify Domain and Path scope, check Expires/Max-Age values, and ensure SameSite settings match your requirements.
Cookie Security Audit
During security reviews, use the cookies analyzer to verify that all session cookies have Secure and HttpOnly flags enabled. Check that cookies with SameSite=None include the Secure attribute, and identify any cookies that might be vulnerable to XSS or CSRF attacks.
Web Development & Testing
When building cookie-based authentication or personalization features, the analyzer helps you verify that your server is setting cookies correctly. Test different attribute combinations and verify the exact cookie format your application depends on.
Browser DevTools Inspection
Copy Set-Cookie headers from browser DevTools (Network tab) and paste them into the analyzer for a clearer view. The analyzer transforms the raw header text into an organized card layout with color-coded attribute badges for easier comprehension.
Learning HTTP Cookie Mechanics
Use the cookies analyzer as a teaching tool to understand how HTTP cookies work. Experiment with different cookie attributes and see how they affect security and behavior. The built-in example presets demonstrate real-world cookie configurations for common scenarios.
Proxy & CDN Cookie Debugging
When debugging cookie-related issues with reverse proxies, CDNs, or load balancers, paste the response headers into the analyzer. Verify that cookies are being forwarded correctly and that no attributes are being stripped or modified by intermediary infrastructure.
Understanding HTTP Cookies and Set-Cookie Headers
What is Set-Cookie Header Analysis?
Set-Cookie header analysis is the process of parsing HTTP response headers that set cookies in a browser. Each Set-Cookie header contains a cookie name-value pair followed by optional attributes. A cookies analyzer decodes these headers into structured data, making it easy to understand each cookie's scope, lifetime, and security constraints. This analysis is essential for debugging web applications, performing security audits, and learning how cookie-based session management works.
How Our Cookies Analyzer Works
Our cookies analyzer uses a custom RFC 6265-compliant parser built entirely in JavaScript. When you paste cookie headers, it splits them by line and parses each one independently. The parser extracts the cookie name and value, then identifies all standard attributes (Domain, Path, Expires, Max-Age, Secure, HttpOnly, SameSite, Priority) and any custom or unknown attributes. Each cookie is displayed in an individual card with color-coded attribute badges and security recommendations. All processing happens locally in your browser with no data transmission.
Key Cookie Attributes Explained
- Secure: Instructs the browser to only send the cookie over HTTPS connections. Essential for preventing cookie theft over unencrypted connections.
- HttpOnly: Prevents JavaScript from accessing the cookie via document.cookie, protecting against XSS attacks. Critical for session cookies.
- SameSite: Controls cross-site request behavior. Strict sends only for same-site requests. Lax allows top-level navigations (modern browser default). None allows all cross-site requests but requires Secure.
- Domain & Path: Define the URL scope where the cookie is valid. Domain specifies which hosts, Path specifies which URL paths on those hosts.
Privacy, Security & Availability
Your privacy is our priority. The cookies analyzer processes everything locally in your browser using client-side JavaScript. Cookie headers you paste are never uploaded, stored, logged, or transmitted to any server. This means you can safely analyze production cookies, session tokens, and authentication data without any privacy concerns. The tool is completely free, with no signup, no API keys, and no usage limits - available whenever you need it.
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