Reputation: 74540
What is Google Analytics' __utm.gif used for (You know that 1px × 1px gif image that loads on every page with Google Analytics)?
I see my screen resolution and other stuff in the URL. Is that how they send all the site's data back to their servers? With a get request on an image? Cause that's kinda uber clever!
Upvotes: 5
Views: 3958
Reputation: 11441
it is a web beacon. Read this: https://en.wikipedia.org/wiki/Web_beacon
Upvotes: 5
Reputation: 298166
The image is dynamically generated and the URL is linked to your account.
When you request the image, Google knows your IP address and some other basic info and can deduce your location, the time of the request, your browser, etc.
The main reason, though, is cross-site-scripting. Requesting an image is easier and completely cross-browser, as you'd have to use JSON to send a request with that information back to Google.
Upvotes: 2
Reputation: 15432
Yes, you are correct. This request is used to send Google details about a particular page request, namely:
Upvotes: 1
Reputation: 887415
Is that how they send all the site's data back to their servers?
Yes.
Upvotes: 1