Your data on Google

Search logs

Have you ever wondered what happens when you type your query into the Google search box and what data we store about that search?

Let’s take a simple search like “cars.” When someone types the word “cars” into the Google search engine, the request gets sent from that user’s computer over the internet to our computers, which look for the right search results. Once our computers have found the results, they send these back to the user’s computer, all in a fraction of a second.

We then store some data about this exchange: the search query (“cars”), the time and date it was typed, the IP address and cookie of the computer it was entered from, and its browser type and operating system. We refer to these records as our search logs, and most websites store records of visits to their site in a similar way.

Here’s what a typical log entry at Google looks like:

123.45.67.89 - 25/Aug/2011 10:15:32 - http://www.google.com/search?q=cars - Chrome 2.0.0.7; Windows NT 5.1 - 740674ce2123e969

But what does this all mean?

IP address:

123.45.67.89 is the IP address assigned to the user’s computer by his or her service provider. Just like other websites, when you ask Google for a page (a search results page, for example), we use your computer’s IP address to ensure that we get the right results back to the right computer.

It’s important to remember that IP addresses don’t say exactly where an individual user is, or who they are. In fact, some Internet Service Providers (ISPs) give users a different IP address every time they log onto the web. The most Google can tell about a user from his computer’s IP address is that user’s general location (for example, Boston) and possibly the ISP they use to connect to the Internet. Only the ISP (who actually controls the user’s account) can match an individual with an IP address.

Time and date:

25/Aug/2011 10:15:32 is the date and time the user typed the query into Google.

Search query:

http://www.google.com/search?q=cars is the search query, in this case “cars.”

Browsers and operating systems:

Chrome 2.0.0.7; Windows NT 5.1 is the browser and operating system being used.

Cookie:

740674ce2123a969 is the unique cookie ID assigned to a browser the first time a user visits Google. Like an IP address, a cookie doesn’t tell Google who a user actually is or where they live – it only identifies a computer. You can delete these cookies at any time in your computer’s browser.

Time limits on data retention

We anonymize IP addresses after 9 months and alter the cookie numbers in our logs permanently after 18 months. This breaks the link between the search query and the computer it was entered from and is similar to the way in which credit card receipts replace digits with hash marks to improve customer security.

Here is what an IP address could look like in our logs after 9 months: 123.45.67.XXX. After 18 months, the cookie will be replaced by a newly-generated cookie number.

Google was the first major search engine to announce time limits on the retention of logs data, and we’re pleased that others in the industry have followed our lead.

Just like cookies in the offline world, online cookies don’t last forever. Google cookies expire after two years. Additionally, Google has always allowed people to use its services without cookies (though this may mean losing the use of some features or functions of particular products).

Why we store search logs

We use search logs for many purposes, for example, to keep our services secure, develop new features that make search faster and more relevant, and even to predict outbreaks of disease. Learn more

It’s good to know what’s stored in a search log when you search on Google. Read the next topic: How ads are targeted by Google

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