Last Updated: May 20, 2022

Google diagnostic is a feature of Google Analytics that makes regular evaluations of your analytics property to identify implementation issues and configuration anomalies via alerts/notifications in a GA view:

However, the biggest limitation of Google diagnostic is that it reports implementation issues on the data you have already collected (in large quantities). Also, it cannot tell you whether an issue has been fixed or not until it can re-crawl web pages and collect more data.

If you want to diagnose implementation issues as soon you have implemented tags and minimize collecting corrupted data, you need to use Google Tag Assistant.

Another limitation of Google diagnostic is that it cannot report implementation issues on the web pages hidden behind Google login or blocked by robots.txt. 

On the other hand, Google Tag Assistant can report implementation issues on such pages.

Introduction to Google Tag Assistant

Google Tag Assistant is a Chrome extension used to identify, validate and troubleshoot the installation of various Google Tags on a web page.

These Google Tags can be:

• Google Analytics
• Google Tag Manager
• Google Ads Conversion Tracking
• Remarketing
• Floodlight etc.

Following are the various functions of Google Tag Assistant:

#1 Display the list of various Google Tags installed on a web page

#2 Report on implementation errors.

#3 Suggest fixes by providing useful tips and link to help articles.

#4 Record user flow across web pages/websites to identify implementation and configuration issues. 

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How to use Google Tag Assistant like a Pro

Step-1: Ensure that you are not using any add-on/extension that disables Google Analytics in your browser. 

For example, I use ‘Google Analytics Opt-out Add on’ to filter out internal traffic. So I need to disable it (via Chrome extension page) before I can use Tag Assistant:

If you are using any such an extension, then turn it off. Otherwise, when you used the Tag Assistant, you may see the following notification:

“No Google Analytics HTTP responses because opted out code detected‘:

Sometimes firewall settings can disable Google Analytics.

Make sure that your settings allow Google Analytics tracking code to execute. Otherwise, Google Tag Assistant may not work correctly and/or produce false-positive results (positive results which are more likely to be false than true).

Step-2: Install the Google Tag Assistant Chrome extension

You need to install the Google Tag Assistant Chrome extension.

Step-3: Enable Tag Assistant

Once you have installed the Tag Assistant Chrome extension, you need to enable it before you can use it on a web page.

To enable Tag Assistant, click on the blue Google Tag Assistant icon on the top right-hand side (next to the browser address bar):

Then click on the ‘Enable’ button and then refresh the web page:

Note: By default Google Tag Assistant is disabled, and it won’t check for any Google tag on a web page.

Step-4: Change Tag Assistant Default Settings

Right-click on the Tag Assistant icon (next to the browser address bar) and then select ‘Options’:

Note: You can also access Tag Assistant ‘options’ setting from within the Tag Assistant window:

Enter one or more domains in the ‘My Favorites’ text box for which you want Tag Assistant to be always enabled, by default:

Note: You can also add a domain to the ‘My Favorities’ list by following the steps below:

1. Navigate to the domain which you want to add as a favorite in Tag Assistant.
2. Enable the Tag Assistant
3. Open the Tag Assistant again and then click on the star icon button

Select the following two checkboxes:

Recording: Follow Links Across Tabs

If this checkbox is not selected, then what will happen is that whenever you use Google Tag Assistant recording, any page which opens up in a new tab or window will not be recorded.

Auto open recordings report when recording is stopped.

If this checkbox is not selected, then what will happen is that whenever you stop your Google Tag Assistant recording, the recording report will not automatically open for you.

You will have to manually click on the ‘Show Full Report’ button to see the recording report:

Navigate back to the Google Tag Assistant ‘Options’ and change the ‘Level of Details’ for all Google tags to ‘Detailed Information’:

Note(1): Ensure that the ‘Default Level’ is also set to ‘Detailed Information’.

Note(2): If you do not want Tag Assistant to check for a specific Google tag, you can turn that tag ‘off’.

For example, if you do not want Tag Assistant to check for the ‘Floodlight’ tag during a page load, you can turn it off by selecting ‘Off’ from the ‘Floodlight’ drop-down menu:

On the contrary, if you don’t find a particular tag being checked and reported by Tag Assistant, make sure that it has not been turned off in the Tag Assistant ‘options’ settings.

Note(3): Every time you change one of the ‘options’ settings, you need to reload the page whose Google tags you want to validate via Tag Assistant.

Step-5: Turn on the ‘Auto Validation’ and ‘GA Debug’ settings

Click on the Google Tag Assistant icon again and then click on the ‘Menu’ button:

Make sure that ‘Auto Validation’ and ‘GA Debug’ settings are turned ON.

Auto Validation ON

By default, Tag Assistant is not enabled across browser tabs.

So whenever you open a new tab, you will have to manually enable Tag Assistant before you can use it.

If you want Tag Assistant to be automatically enabled across all browser tabs, turn on the ‘Auto Validation’ setting.

GA Debug ON

When you turn on the ‘GA Debug’ setting, it is equivalent to using the Google Analytics debugger Chrome extension.

In other words, you do not need to install and use the Google Analytics debugger Chrome extension when the ‘GA Debug’ setting of the tag assistant has been turned on.

Different colours of Google Tag Assistant icons and what they mean

When you navigate to a web page where Tag Assistant is enabled, you are going to see the Tag Assistant icon with one of the following colours:

• Green
• Blue
• Yellow
• Red

Tag Assistant Icon in Green Colour

If you see the Tag Assistant icon in green, then it means Tag Assistant has found all of the identified Google Tags to be perfectly valid.

Tag Assistant Icon in Blue Colour

If you see the Tag Assistant icon in blue, then it means Tag Assistant has found Google tags that have no major or minor implementation issues but which are still not perfectly valid tags because of some non-standard GA implementation.

Tag Assistant Icon in Yellow Colour

If you see the Tag Assistant icon in yellow, it means Tag Assistant has found some or all Google tags with minor implementation issues.

Tag Assistant Icon in Red Colour

If you see the Tag Assistant icon in red, then it means Tag Assistant has found some or all Google tags with major implementation issues.

Number in the Tag Assistant icon

You will also notice a number in the middle of a Tag Assistant icon:

This number represents the number of tags identified by Google Tag Assistant on a web page.

For example, if the red icon has got number 6 on it, then it means there are 6 Google tags identified by Tag Assistant.

However, this number does not automatically imply that all 6 Google tags have got major implementation issues.

Note: Google Tag Assistant works only on those web pages which have got at least one of the Google tags.

So if you try to use this tool on a page with no Google tag, you won’t see any result and you may be asked to add Google Analytics to your website:

Open Google Tag Assistant in a separate browser tab

Load that web page into your browser window whose Google tags you want to identify, validate or troubleshoot.

Click on the Google Tag Assistant icon again and then click on the ‘Menu’ button, followed by ‘Show in separate tab’:

The ‘Show in separate tab’ menu item will open the Google Tag Assistant in a separate browser tab.

If you do not use this option, then every time you navigate to a different browser tab or reload the web page, the Google Tag Assistant window will automatically hide, which will become annoying for you really fast.

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Understanding Google Tag Assistant results

Once you open Tag Assistant in a separate browser tab, you will see the result of tag analysis:

From the result above, we can conclude that:

#1 A total of 12 Google tags have been identified on the page by Tag Assistant.

#2 One tag has got an error (major implementation issue).

#3 The list of visible tags in the Tag Assistant window are: Remarketing Tag, Floodlight, Google Analytics and one other Google Analytics.

#4 Since the Google Analytics tag is displayed twice, and both tags have different property IDs, it means the web page is using two different trackers.

The ‘Where to optimize’ section shows general notifications or errors which do not necessarily relate to a specific tag but which require your attention.

However, when you click on a particular tag within the Tag Assistant window, the ‘Where to optimize’ section provides a more specific notification/fix:

#6 The red, yellow, blue and green icons next to identified tags have all got special meaning:

Click on one of the tags in the Tag Assistant window:

You can now see the ‘Meta Data’, ‘Code Snippet’ and ‘Where to optimize’ information for the selected tag:

Meta Data

The meta data can contain:

• Web Property ID
• Google Tag Manager Container ID
• Code Version/Syntax

Where to Optimize

The ‘Where to Optimize’ section includes notifications and links to help articles related to the selected tag.

For example, if you hover your mouse over say ‘No HTTP response detected‘ notification, you will see additional notification pop up box + the ‘? ‘ button:

Click on the ‘?’ button will redirect you to one of the Google help articles related to the ‘No HTTP response detected‘ issue.

Through this help article, you can troubleshoot this problem.

Font colour of the notification text under ‘Where to Optimize’.

You also need to pay attention to the font colour of the notification text under ‘Where to Optimize’.

The notification ‘No HTTP response detected‘ is in red colour, which means it is a major implementation issue and needs to be fixed ASAP.

The notification ‘Code found outside of <head> tag‘ is in blue colour, which means it is neither a major nor a minor implementation issue but is still not perfectly valid because of non-standard implementation.

You can choose to ignore this issue.

The ‘Code Snippet’

The ‘Code Snippet’ section provides the actual code you can look at for troubleshooting:

Click on the ‘View Source’ link if you want to see the code in a different tab along with other website code.

Depending upon the tag you are analysing, you will see different types of data for different tags.

For example, if you click on the Google Tag Manager tag, then you can see the data layer being used on a web page:

Analyzing individual GA hits through Google Tag Assistant

Through Google Tag Assistant, you can also analyse individual Google Analytics hits.

To do that, follow the steps below:

1. Click on a tag in the Tag Assistant window
2. Scroll to the bottom
3. Look for links related to request/hit:

The ‘Pageview Request‘ link is the pageview hit.

Click on this link to see more details (Metadata and GIF request) about this hit:

If you click on the ‘URLs’ link, you can see the GIF request sent to the GA server:

However, this GIF request is hard to read, so click on the ‘table’ button to see the GIF request in tabular format:

To learn about the recording feature of Google Tag Assistant, read this article: Guide to Google Tag Assistant Recordings.

New Google Tag Assistant

Google has now introduced a new Tag Assistant that allows you to verify and troubleshoot tagging for global site tag (gtag.js) and also Google Tag Manager installations. Basically, the new preview mode in Google Tag Manager is now replaced with the Tag Assistant.

For the new Tag Assistant, you don’t need to install the Chrome extension and it comes with additional features. Let’s discuss the new assistant in detail and how to access it.

To access the new Tag Assistant, follow the below steps:

Step-1: visit https://tagassistant.google.com/

Step-2: Click on the ‘Add Domain’ button once the page is loaded.

Step-3: A dialog box will pop up when you click on ‘add domain’ enter the URL of the domain that you would like to debug.

Step-4: Enter the URL, for example, https://www.optimizesmart.com/ and click on ‘Start’.

Step-5: A new tab will open that adds gtm_debug=x in the URL as shown below.

Step-6: Also, on the website, you will see a notification as shown below, which states ‘Debugger connected’.

Step-7: Once Tag Assistant is connected, you would see the status as shown below. Click on ‘Continue’ to view the tags fired.

Step-8: For every action that you perform on the site, you will notice the tags fired in the tagassistant.google.com tab.

Step-9: You can click on the summary, and it will show you all the tags fired on a particular action on the website.

Step-10: Click on the ‘X’ symbol to stop debugging in the panel.

Step-11: Additionally, you can also stop debugging from the Tag Assistant tab. Click on ‘Stop debugging’.

Step-12: In the history, you can see all the domains that you have worked for debugging.

Step-13: When you click on the 3 dots next to the domain name, you will see options to edit, share and delete.

Step-14: When you click on the ‘Edit’ option, a new pop up appears where you can edit the domain name. You can make changes to the domain name if required and click on ‘Apply’.

Step-15: When you click on ‘Share’, a new pop up appears, which will let you share the debug session with anyone.

Note: You can copy the link from a shareable debug link and share it with anyone; this will enable a Tag Assistant debug session for them.

Step-16: When you click on the ‘Delete’ option, the domain will be deleted from Tag Assistant.

Other articles you will find useful:

• Understanding Google Analytics Diagnostic messages and notifications
• Introduction to Piwik – Best Google Analytics Alternative

Frequently Asked Questions About Google Tag Assistant