How to Send Cookies in Request Headers

To send cookies to a server, include them in the HTTP request header using the Cookie: name=value format. If you need to send multiple cookies in a single request, separate them with semicolons. Servers typically store cookies in a client’s browser by returning the Set-Cookie: name=value header in the server’s response. Here’s an example where cookies are sent to the blogshub echo URL in the HTTP request header. Click “Send” to execute the example and view the results.

What is HTTP?

HTTP, or Hypertext Transfer Protocol, is the foundation of data communication on the World Wide Web. It enables the transfer of data between clients (such as browsers or mobile applications) and servers. HTTP operates on a request-response model, where:

• The client initiates a connection and sends a request.
• The server processes the request and responds with the appropriate data.

This protocol ensures seamless interaction between web applications and their users.

What are HTTP Cookies?

HTTP cookies are small text files created by a server and stored on a user’s device via a web browser. These cookies carry unique identifiers that allow the server to recognize repeat visits from the same browser. The browser automatically sends these cookies back to the server with each subsequent request, enabling the server to:

• Authenticate users.
• Provide personalized content.
• Manage user sessions efficiently.

Cookies are essential for enhancing user experiences, tracking behavior, and storing preferences such as themes and settings.

Syntax of the Cookie Header

The syntax for sending cookies in an HTTP request header is as follows:

Cookie: name=value; name2=value2  

Why Are Cookies Important?

Cookies serve three primary purposes:

1. Session Management
   They help websites remember login details, user credentials, and other session-specific data.
2. Personalization
   Cookies enable customized user experiences, including preferred themes, layouts, and settings.
3. Tracking
   They record user behavior for analytics, providing insights into browsing habits and enabling targeted advertisements.

How to View Saved Cookies in Your Browser

To check cookies stored by a website:

1. Open the website in your browser.
2. Press F12 to launch developer tools.
3. Go to the Application tab.
4. In the Storage section, click on Cookies and select the website URL.
5. You’ll see all cookies stored for the selected site.

Sending Cookies: An Example

Here’s a simple example of how to send cookies to a server using the HTTP header:

GET /example-path HTTP/1.1  
Host: example.com  
Cookie: sessionId=abc123; theme=dark  

This approach ensures the server can identify the client and provide the appropriate response, creating a smooth and personalized user experience.