FAQ

What is Google Correlate?

Google Correlate is a tool on Google Trends which enables you to find queries with a similar pattern to a target data series. The target can either be a real-world trend that you provide (e.g., a data set of event counts over time) or a query that you enter.

What information is provided by Google Correlate?

Google Correlate uses web search activity data to find queries with a similar pattern to a target data series. The results can be viewed on the Google Correlate website or downloaded as a CSV file for further analysis.

How is Google Correlate different from Google Trends or Google Insights for Search?

Google Correlate is like Google Trends in reverse. With Google Trends, you type in a query and get back a data series of activity (over time or in each US state). With Google Correlate, you enter a data series (the target) and get back a list of queries whose data series follows a similar pattern.

How up to date is the information provided by Google Correlate?

Google Correlate contains web search activity data from January 2003 to present. This data is updated weekly.

What’s the difference between comparing US states and comparing time series?

Google Correlate lets you search in two different ways. The US states option lets you find queries which have similar state-by-state patterns. The time series option lets you find queries that have similar patterns across time. For more information, see the Google Correlate Tutorial. 

How can I use the information I find on Google Correlate?

You're free to use any of the information you find on Google Correlate, subject to the Google Terms of Service. Please attribute it to Google as follows: "Data Source: Google Correlate (http://www.google.com/trends/correlate) ".

What are the units for the data in the chart and CSV file download?

The units are standard deviations above mean. If you download any data, you should find that all of the time series have mean 0 and standard deviation 1. For more information see this Wikipedia article on  standard score.

How should I format my CSV file for upload to Correlate?

For us-weekly data, your csv should be of the form:

YYYY-MM-DD,value

where YYYY-MM-DD are weeks starting on Sundays.

For us-states data, your csv should be of the following form:

State Name,value

Note that for both CSV files, comment lines (starting with a # character) are ignored.

How will Google use data sets that I upload to Google Correlate?

We will not use any of your content for any purpose except to provide you with the Google Correlate Service, monitor traffic and detect spam and fraud. See the Terms of Service  for more information.

This tool makes search information public. What about my personal search data?

Your personal search data remains safe and private. Our graphs are based on aggregated data from millions of Google searches over time. Moreover, the results Google Correlate displays are produced by an automated system. See our Privacy Center for more about how we use search query data.

How do you determine the location of a query?

Google Correlate uses IP address information from our server logs to make a best guess about where queries originated.

Can you tell more about what Google does with my personal search data?

Please read more at the Google Privacy FAQ.

How has sampling changed for Google Correlate?

In December 2011, we added support for time series correlations on a number of new countries. As part of this change, we reduced our sample size for US states and US time series to match that of the other countries. While this does not have much of an effect on popular queries, it may cause a noticeable increase in variance for queries with lower volumes.

Have an interesting finding you want to tell us about? A technical problem? A feature request? A question not answered by this FAQ?

Please send us feedback!