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HTTP Header
Cookie
RequestSends previously stored cookies from the client to the server.
HTTP header reference, syntax, examples, and developer usage.
What is the Cookie header?
The Cookie HTTP header is used to transmit metadata between a client and server as part of HTTP requests or responses.
HTTP headers define how content should be interpreted, cached, authenticated, secured, or processed by browsers and APIs.
Direction
This is a request header sent by the client to the server.
Syntax
Cookie: name=value
Example
Cookie: session_id=abc123
Common use cases
- Sessions
- Authentication
- Preferences and tracking
Common mistakes
- Using the header in the wrong request or response context
- Sending invalid header values
- Incorrect header syntax
- Assuming the header automatically changes server behaviour