Cookie Decoder — Free Online HTTP Cookie Parser
Parse Cookie and Set-Cookie headers into structured key-value pairs with decoded values — 100% client-side.
Frequently Asked Questions
HTTP Cookie Headers Explained
HTTP cookies are small pieces of data sent by servers and stored by browsers. They are used for session management, user preferences, and tracking. Understanding cookie structure is essential for debugging authentication flows, session handling, and security issues.
The Cookie request header contains all cookies the browser has stored for a domain, sent with every request. Values are semicolon-separated name=value pairs and may be URL-encoded.
The Set-Cookie response header sets a new cookie. It includes the name/value and optional directives: Secure (HTTPS only), HttpOnly (no JS access),SameSite (CSRF protection), Domain, Path, andExpires / Max-Age.