Is there a way to detect if a user is using the same device/browser on a web page e.g. If the user enters the site in the morning with a laptop, the client-side sends a token to the server and if the user enters the site in the evening with the same laptop or device, the client-side must send the same token.
The possibility that comes to mind is saving a token in a cookie and getting it back later, but it is very unsafe.
using a session cookie is the right way to do this.
HOWEVER if you are totally opposed to cookies, you could use localStorage with a random value
if (!localStorage.getItem("token")) {
localStorage.setItem("token", Math.random());
}
// You can then make an ajax call with your token