Addressing Unexpected Data Discrepancies

This FAQ guide is designed to help you navigate through common challenges that might lead to unexpected data discrepancies in Matomo. If you are comparing Matomo reports to other web analytics tools and noticing discrepancies between them, please see Why do Matomo data reports differ from Google Analytics and other analytics tools?

Unexpected decrease in traffic

Checking for Tracking Failures:

In Matomo, the « Tracking Failures » report found in Administration > Diagnostics > Tracking Failures provides insight into any issues that might be affecting your tracking. This report lists any tracking requests that have failed, helping you identify potential problems in the data collection process. Investigate any failures listed here to understand the reasons behind the decrease in hits.

Some examples of tracking failure messages you may receive:
Request was not authenticated but should have
The site does not exist

Verifying Tracking Code Installation:

Examining the source code of your web pages (« View Source« ) is a crucial step to ensure that the Matomo tracking code is still present and correctly implemented on your website. If the tracking code is missing or improperly placed, it could lead to a decrease in recorded hits. Make sure the tracking code is placed between the head tags on all pages you want to track. You can always confirm the tracking code of your website from within your Matomo dashboard from Administration > Websites > Tracking Code.

Checking for Multiple Trackers:

Having multiple instances of the Matomo tracking code on your website can lead to data discrepancies and reduced hit counts if incorrectly configured. Use your browser’s console window to inspect the network requests and confirm if multiple trackers are firing. This can help you identify any conflicts or duplication’s that might be causing the issue.

To ensure you have the correct setup for multiple trackers, please see the following page – How do I send tracking requests to two or more Matomo servers?

Server or Hosting Issues:

Server downtime, slow page loading times, or hosting-related problems can affect the tracking process. If visitors are unable to access your website, it will naturally lead to a decrease in hits. Monitor your website’s performance and uptime to rule out any server-related issues.

Changes made within your Matomo Dashboard:

Unanticipated declines in hits may occur from alterations made within your Matomo Dashboard. For instance, if one of your user’s modifies website settings to restrict tracking to specific URLs, such changes can affect hit counts. To investigate this, examine the access logs to determine if any recent adjustments have been made to your website. If you are logged as a super user, you will get an overview and a detailed report about who accessed Matomo and which actions they performed. You can find the access logs from Administration > Diagnostic > Activity Logs.

Consent Tool Configuration:

Consent tools play an important role in data collection, especially in the context of user privacy and legal compliance. Sometimes, consent may be required to load specific analytics scripts, such as Google Analytics (GA) or Matomo. If consent is not obtained or is granted for one script but not another, it can lead to discrepancies in your data.

Ensure that your website’s consent tools are correctly configured and check whether you are obtaining user consent for both Matomo and any other analytics scripts you may use, such as GA.

For detailed guidance on implementing consent tools in Matomo, please see our consent guides.

Unexpected increase in hits

Duplicate tracking:

A common occurrence of duplicate page views can occur when both the standard JavaScript tracking method and the Tag Manager tracker (configured with a pageview tag/trigger) are concurrently employed. This dual tracking approach can result in the unintended tracking of a single page multiple times.

An additional scenario may arise when the Matomo tracker is set up within Google Tag Manager (GTM), but you also have a standalone Matomo tracker installed directly on your website. In this situation, it’s essential to ensure the presence of only a single instance of the Matomo tracking code to prevent duplication and maintain accurate data collection.
To troubleshoot instances of duplicate tracking on your website, a helpful approach involves utilizing your browser’s web console. In the majority of modern browsers, you can access the console by right-clicking anywhere on your webpage and selecting ‘Inspect’. This action will show the browser console window. Proceed to the Network tab and input ‘Matomo’ in the filter field before reloading your webpage.

Subsequently, you will be able to observe the firing of the Matomo tracking code for the page view. In the example below, it’s evident that matomo.js has been activated twice, along with the Tag Manager container. This results in a scenario where the single page view is tracked a total of three times. The below screenshot is an example of the Matomo tracking code being fired 3 times for a single page view.

Referrer Spam:

Referrer spam is a type of spamming tactic targeted at web analytics tools. In this practice, a spammer employs automated bot software to generate a series of fake requests to a website. These requests contain fabricated referrer URLs, falsely indicating the source of the traffic. The purpose of referrer spam is to manipulate the reported referral sources in the website’s analytics data, often with the intent of promoting specific websites or services.

Referrer spammers are automatically excluded from your reports to keep your data clean and useful.
New spammers are continuously detected and added to Matomo’s blacklist on each update. If you find a new spammer in your analytics data, you can even report it so that it is added to Matomo open referrer blacklist and blocked for everyone.

Bot Traffic

Bot traffic can cause an increase in recorded hits on your website. Bots are automated programs that perform various tasks, such as scanning for security issues, assisting search engines, or spamming. When bots interact with your website by loading pages, clicking links, or performing other actions, each of these actions is counted as a hit.

Because bots can navigate quickly and perform actions rapidly, they can generate many hits in a short period. This can lead to an inflated count of hits, making it seem like there’s more activity on your website than there really is.

Some of the visits with a specific user-agent will be detected by Matomo as a bot, and won’t be tracked. You can test if a User-Agent is detected as a bot from within your Matomo dashboard Administration > Diagnostic > Device Detection. In the “User-Agent” text field, copy/paste the user agent you want to check. An example of a search engine bot would be: Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)

To exclude traffic for a particular User agent (or several user agents), go to Administration > Settings under the Websites (or Measurables) section. Below the list of websites, you will find the option to specify “Global list of user agents to exclude”. You can enter here a list of user agents to exclude from being tracked by Matomo. It is also possible to exclude useragents using a regex pattern such as /bot|spider|crawl|scanner/i.

You may also be interested in Visits and clicks data provided by search engines or ad networks or affiliates do not match the acquisition reports in Matomo.