Why do I see discrepancies between Supermetrics results and the Google Analytics web interface?

While most of the time, Supermetrics matches exactly the figures that the Google Analytics web interface displays, sometimes there are discrepancies. There are two common reasons for these discrepancies:

Data Sampling

Google samples the results it delivers to Supermetrics. In some cases, Google uses sampling to calculate the results of queries, which can cause differences between Supermetrics and Analytics. The magnitude of the discrepancies is usually in the range of 1-4 %. To see whether Google has sampled your query results, open the SupermetricsQueries sheet (for example, from the Add-ons menu click Supermetrics->Manage queries) and see whether the "Results contain sampled data" row has the value TRUE or FALSE. Sampling occurs most often in queries that include an advanced segment, very large data sets, or where the data is split by multiple dimensions.

Note - Data Studio does not have a way to check for this.

You can in some cases avoid data sampling by using the following setting:

Be aware that this can slow down your query and increases the request amount needed for the query, leading to potential quota issues. Queries that are large/complex enough will still be sampled by Google, even with this setting enabled.

API and Web Interface Out-of-Sync

The Google Analytics API and the Google Analytics web interface are not always totally in sync. Supermetrics relies on the Google Analytics API, which may in some cases deliver figures which differ from the Analytics web interface. Small differences can be seen every now and then, but sometimes bugs in Google's end cause major discrepancies. 

If you suspect something like this may be affecting your reports, there are a few places where you can investigate the issue:

  • Analytics status dashboard. Here you can see the status of the Analytics API and other Analytics services, bugs may be shown here.
  • Analytics API notify list. Serious issues may be posted here by Google.
  • Analytics query explorer. This is Google's own API tool, which you can use to confirm the results showed by Supermetrics Data Grabber. If this tool agrees with Supermetrics and differs from the Analytics web interface, then it indicates a bug in Google's end. On the other hand, if Google's API tool and the Google Analytics web interface match, and Supermetrics shows something different, that indicates a problem in our end; in this case, please contact us immediately.

When you see a discrepancy, before notifying us of the issue, please follow these steps:

  1. Check whether the query results are based on sampled data (select query and click Modify). If this is the case, and the discrepancy is just a few percent, then it's very likely caused by the data sampling.
  2. Try to fetch the same data with Google's own API tool. If the results match Supermetrics, then the issue is in Google's end and we can't fix it.

If you if have ruled out the above reasons for the discrepancy and believe it to be an issue with Supermetrics, then submit a support ticket that includes screenshots showing the differences between Supermetrics results and Analytics. Make sure the date ranges are exactly the same in each screenshot.