Feature: Site Preview Images (Thumbnails)
The preview images that are inserted into the search results page are standard html images. Your browser requests the images from a SearchPreview image server (depending on your location eu1. or jp. or nyc. or sfo.searchpreview.de/preview or /x2 for retina preview images) via the HTTPS protocol, this request contains the following information:
-the request for the preview image
-the referrer site (the site the image was embedded in, for example https://www.google.de/)
-the user agent (a string identifying the browser you are using, for example Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36
Every HTTPS request contains the above data, see the RFC 2616 (http://www.w3.org/Protocols/rfc2616/rfc2616.html) for a detailed description of the protocol details. The request for the preview image (for example https://eu1.searchpreview.de/preview?s=http://www.mozilla.com&ua=Chrome&ver=833) contains the site of the image that is requested, a user agent flag stating which Browser is used and the version number of the SearchPreview engine.
Your IP address is required for the transmission of above data between your Browser and the SearchPreview image server, however the SearchPreview server software does not read, process or hold your IP Address.
The SearchPreview image server will log every request in a log file on disk, in addition to above data the following data is logged per request: Time, bytes transferred, duration of request, http code. These log files are not sold or given to third parties and are automatically deleted after 10 days. The only purpose of the log files is to monitor performance and traffic usage.
You can disable the Site Preview Images feature in the SearchPreview options area, in this case no data is sent to / requested from the SearchPreview Preview Image servers.
Feature: Site Popularity Ranks
The site popularity ranks are provided by Alexa Internet Inc., an amazon.com company. To receive the site popularity ranks of the sites in the search results page SearchPreview executes a HTTPS request to a SearchPreview server (depending on your location eu1. or jp. or nyc. or sfo.searchpreview.de). In addition to the normal HTTPS protocol data (see above) this request contains a typical Google referrer (containing the google domain, search term, time of search and result page number) and the URLs of the sites in the search results page. The response contains the rank values for the search results. The SearchPreview server forwards this request via HTTPS to an Alexa Server, which in turn returns the rank values.
You can disable the Site Popularity Rank feature in the SearchPreview options area, in this case no data is sent to / requested from a SearchPreview server and Alexa Internet Inc.