Cookie Parser
Deconstruct browser cookies and Set-Cookie headers into structured key-value attributes with security flag auditing.
Active Session Stats
Parsed 1 cookie(s) in active input.
In-Browser Cookie Header Analysis and Security Auditing
The Cookie Header Parser provides a local diagnostic workbench for analyzing HTTP Cookie request headers and Set-Cookie server response directives. Web developers and security engineers need to inspect cookie strings to verify proper session configuration and security attribute flags.
This utility parses raw cookie strings according to RFC 6265 specifications, breaking down complex semi-colon delimited strings into structured key-value pairs. Each attribute (Domain, Path, Expires, Max-Age, Secure, HttpOnly, and SameSite) is extracted and verified client-side.
The parser flags potential security vulnerabilities such as missing HttpOnly protection on session tokens, absent Secure flags over HTTPS, or overly permissive SameSite configurations. All decoding and auditing execute inside your browser without transmitting sensitive tokens.
Core Tool Capabilities
- RFC 6265 Syntax Deconstruction: Splits raw Cookie and Set-Cookie header lines into distinct token keys, values, and directive flags.
- Security Flag Verification: Audits presence of HttpOnly, Secure, and SameSite (Strict, Lax, None) flags to highlight transport risks.
- URL Percent-Decoding: Automatically unescapes percent-encoded cookie values, JSON payloads, and serialized session structures.
- Expiration and Lifetime Calculation: Parses GMT timestamp strings and Max-Age seconds to calculate exact remaining cookie lifespans.
Local Browser Privacy
Your files are processed locally on your device. Files are not uploaded, transmitted, or stored on remote servers.
Once the page has loaded, you can disconnect your network connection and continue using this tool offline.
Target Use Cases
- • Web Application Security Auditing
- • Authentication Debugging
- • API Gateway Header Verification
- • Privacy and Tracking Compliance
Technical Specifications and Platform Limits
Conforms to IETF HTTP State Management Mechanism specifications
Evaluates flags against OWASP cookie security best practices
Performs token deconstruction locally without outbound network calls
Sensitive authentication cookies are never logged or stored
Step-by-Step Workflow
Paste Raw Cookie String
Copy a Cookie header from browser developer tools or a Set-Cookie header from a server response into the input box.
Execute Local Parsing
The parser automatically decodes percent-encoded characters and extracts attribute directives.
Inspect Security Posture
Review the extracted attributes table and verify whether Secure, HttpOnly, and SameSite flags are enabled.
Export Structured JSON
Copy individual cookie values or export the complete decoded attributes list as formatted JSON.
Practical Real-World Use Cases
Web Application Security Auditing
Penetration testers and security analysts verifying that sensitive session identifiers are protected with HttpOnly and Secure flags.
Authentication Debugging
Full stack developers troubleshooting cross-origin cookie delivery and SameSite attribute mismatches in modern browsers.
API Gateway Header Verification
DevOps engineers inspecting proxy and load balancer headers to confirm correct cookie transformations.
Privacy and Tracking Compliance
Compliance auditors identifying first-party and third-party tracking cookies across website responses.
Frequently Asked Questions
- Are my private session cookies uploaded to remote servers?
- No. All cookie parsing, URL decoding, and security auditing occur entirely inside your local browser memory.
- What is the purpose of the HttpOnly flag?
- The HttpOnly flag prevents client-side scripts from reading cookie values, mitigating cross-site scripting (XSS) session theft.
- Does the parser support both Cookie and Set-Cookie syntax?
- Yes. The parser understands both semicolon-separated Cookie request headers and single Set-Cookie response directives.
- How are SameSite attributes evaluated?
- The parser highlights whether cookies declare Strict, Lax, or None, warning if SameSite=None is used without the Secure flag.
- Can the tool decode URL-encoded values automatically?
- Yes. Percent-encoded values inside cookie payloads are unescaped automatically into human-readable text.
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