第一次请求时未发送Cookie

Question

I am trying to understand cookies and what causes them to be sent as part of a request. My basic understanding of cookies is that they are name value pairs that get sent with every request based on the path variable. I am doing a basic test that seems to suggest that cookies are not sent on an initial request. My test is this.

1. Open up a chrome incognito mode.
2. Press F12, enter document.cookie = "test_value=test_name;path=/;" into the console.
3. Go to google.com.

Now if I look at the network tab and look at the request to google.com. Under the cookies tab I can see that no cookies were sent with the request. Why not?

Furthermore, once I am at www.google.com, if repeat steps 2 and 3 in the above procedure, the cookie does get sent this time. Not only does it get sent, I get 4 response cookies.

So why does the cookie not get sent the first time, and why do I get 4 response cookies the second time?

Answer 1

The first page Google Chrome shows when user starts incognito mode is handled differently from the other ones. It doesn't share browser resources (like cookies storage, ...) with Internet pages. If you try with another page you'll see that it works correctly.

For example, if you go to www.example.com , type document.cookie = "testCookie=value; path=/" in JavaScript console and refresh the page you'll see the header Cookie containing it in HTML request.