Google Trends for Websites is one among the few online tools that you may use to get an idea of a website’s traffic. Simply provide the address (URL) of the website and the tool will give you a rough estimate of the number of people who visit that site per day (unique visitors).

For instance, this report generated by Google Trends seems to suggest that the Wikipedia website, on an average, gets around 40 million unique visitors daily.

But how accurate is Google Trends data? I was recently comparing the Google Analytics data with Google Trends for labnol.org and, surprisingly, the results were vastly different. See these Google Trends and Google Analytics charts for the same period.

Google Analytics Chart for labnol.org

Google Trends Chart for labnol.org

The Google Trends chart for this site seems to suggest that global traffic (daily unique visitors) has been on a constant decline since March 2011 and almost hit the December 2008 level. However, another data source - Google Analytics - paints a very different picture.

Analytics puts the daily visitor count at 100K while Trends calculates that number as 50K. Yes, there was a dip in March when Panda struck but the site recovered soon thereafter.

Anyone else seeing such a discrepancy for their site in Google Trends?