Cookie Parser
Free online cookie parser tool. Parse and inspect Set-Cookie headers and document.cookie strings to view names, values, and attributes.
What Is a Cookie Parser?
HTTP cookies are small pieces of data that web servers send to browsers via the Set-Cookie response header. Browsers store these cookies and include them in subsequent requests using the Cookie header. Cookies are fundamental to web development — they manage user sessions, store preferences, track authentication state, and enable personalization. A Cookie Parser breaks down raw cookie strings into their individual components: the cookie name and value, along with attributes like Expires, Max-Age, Domain, Path, Secure, HttpOnly, and SameSite. This tool supports parsing both Set-Cookie headers (server response format with attributes) and document.cookie strings (browser-side format with multiple key-value pairs).
How to Use the Cookie Parser
- Select the parsing mode: 'Parse Set-Cookie' for server response headers or 'Parse Cookie String' for browser-side cookie strings.
- For Set-Cookie headers: paste the full header value (e.g., 'session_id=abc123; Path=/; HttpOnly; Secure'). The tool will extract the cookie name, value, and all attributes.
- For Cookie strings: paste the document.cookie value (e.g., 'key1=value1; key2=value2'). The tool will split it into individual cookie key-value pairs.
- Review the parsed output showing each component in a structured, easy-to-read format.
Common Use Cases
- Debugging Authentication Issues — Inspect Set-Cookie headers from authentication endpoints to verify cookie attributes like HttpOnly, Secure, SameSite, and expiration are set correctly.
- Security Auditing — Check whether cookies have proper security flags (Secure, HttpOnly, SameSite) to prevent XSS attacks, CSRF vulnerabilities, and cookie theft.
- Cross-Domain Cookie Troubleshooting — Analyze Domain and Path attributes to diagnose issues with cookies not being sent to the expected subdomains or URL paths.
- Session Management Review — Parse session cookies to verify expiration times, understand Max-Age settings, and ensure session cookies are configured according to security best practices.