Explanation
The error “window.gtag is not a function” occurs when the gtag
function is not defined or is not accessible from the window
object.
Possible Causes
- The Google Analytics tracking code is not properly implemented.
- The Google Analytics script is not loaded before calling the
gtag
function. - There might be another script or third-party library conflicting with the
gtag
function.
Possible Solutions
- Ensure that you have included the Google Analytics tracking code properly in your HTML file, following the instructions provided by Google.
- Make sure the Google Analytics script is loaded before any code that calls the
gtag
function. It is recommended to include the script in the head section of your HTML file. - Check for any potential conflicts with other scripts or third-party libraries. Sometimes, different scripts can use the same variable names, causing conflicts.
Example
Here is an example of a correct implementation of the Google Analytics tracking code:
<!-- Google Analytics tracking code -->
<script async src="https://www.googletagmanager.com/gtag/js?id=UA-XXXXXXXXX-X"></script>
<script>
// Initialize Google Analytics
window.dataLayer = window.dataLayer || [];
function gtag(){dataLayer.push(arguments);}
gtag('js', new Date());
gtag('config', 'UA-XXXXXXXXX-X');
</script>