How to Compare More Than 5 Keywords in Google Trends (on One Scale)

Google Trends limits the number of keywords you can compare at once to five. When trying to compare more than five search terms, separate comparisons cannot be combined as each chart is normalized to its own peak, creating a 0-100 scale. To compare more than five keywords, analysts use an anchor term with medium, steady popularity.

This anchor term is used to split other keywords into groups of four and query them together with the anchor term. Each group will have different values for the anchor term because each chart has its own peak.

To make all groups comparable on the same scale, compute a scale factor for each group by dividing the sum of the anchor term in the first group by the sum of the anchor term in the current group. Multiply every value in the group by its corresponding scale factor. This will bring all groups onto the anchor term's scale. Finally, re-normalize everything to a 0-100 scale using the overall maximum value.

For example, if the true interest is anchor = 10, X = 40, and Y = 20, in Group 1 (anchor, X), Google shows anchor = 25, X = 100. In Group 2 (anchor, Y), Google shows anchor = 50, Y = 100. The factor for Group 2 is 25 / 50 = 0.5, so Y becomes 50. The final results are X = 100, Y = 50, anchor = 25, which accurately represents the true values of 40, 20, and 10.

To simplify this process, a cloud tool called Google Trends API & Scraper has been created on Apify. This tool takes a list of keywords, allows you to choose one or more countries, and returns every keyword on a single comparable 0-100 scale. It also provides a CSV table for Excel or Sheets and handles Google rate-limiting issues through residential proxies. To use this tool, you need to provide your Apify token and configure the search terms, comparison terms, geo locations, and time range.