Short answer: Google Tag Assistant is Google’s troubleshooting tool for the tags on your website. You connect it to your site at tagassistant.google.com, then browse your own pages while it lists the tags, events and data each page sends. Google recommends its Chrome extension for pages that load the tag in an iframe or open new tabs.
What Tag Assistant shows
Google describes Tag Assistant as a troubleshooting tool that helps you check how the tags on your website are set up and whether they work. You can review the tags, events and data on your site, export and import debug sessions, and share a debugging link so someone else can debug for you.
When your site has the Google tag or a Google Tag Manager container, Tag Assistant adds the pages it sees to a Tag coverage summary. It lists tagged and untagged pages, so you get an overview of how much of your site is tagged.
Google also says the debug information isn’t visible to your regular visitors. The debug window stays open while you move around the same domain, as long as the Google tag is on the page.
The Tag Assistant Chrome extension
Google recommends installing the Tag Assistant Chrome extension. With it, Tag Assistant can find the Google tag inside an iframe and debug pop-up windows or new tabs opened from your page.
The extension also opens the debug window in a new browser tab instead of a pop-up, and lets you debug several windows in the same session.
The old Tag Assistant Legacy and Tag Assistant Companion extensions are now one extension with both sets of features. If you use Legacy, you don’t need to uninstall anything, since it updates itself. Companion is uninstalled automatically once the new extension is updated.
From the extension, Troubleshoot tag opens tagassistant.google.com in a new tab and starts a debug session.
How to connect Tag Assistant to your website
- Go to Google Tag Assistant at tagassistant.google.com.
- Click Add domain.
- Enter the address of the page you want to check, starting with https:// or http://.
- If you want more detailed logs, check Enable verbose logging.
- Click Connect, then click through your site as a visitor would.
The steps come from Google’s Tag Assistant Help. To stop, click Stop Debugging or the X in the debug window.
When Tag Assistant connects, it adds a debug parameter, _dbg, to the end of your URL. Google says that parameter helps you view your events in other debugging tools, such as DebugView in Google Analytics. Our GA4 DebugView guide shows what to look for there.
If you use Google Tag Manager, its Preview button opens Tag Assistant for your container before you publish. Our Google Tag Manager guide walks through that check.
When Tag Assistant won’t connect
Google lists these causes and fixes. The page you entered may not have the Google tag, so try another page where you expect it. The debug parameter may change how the page behaves; in that case, edit the domain and turn off Include debug signal in the URL.
The tag script may load after Tag Assistant tries to connect, and Retry connects again. AMP pages aren’t supported for now, and a tag loaded in an iframe can only be debugged with the Chrome extension installed.
Several redirects in a row can stop the debug window from loading. Ad blockers can stop the Google tag from running, so turn them off for the pages you test. With the extension installed, check that it may read and change site data on those pages.
Consent management tools can block Google tags too. Google asks you to set them up so they work with its consent API.
In our view, test with the same consent choice a visitor would make. A tag that stays silent until someone accepts cookies is doing its job.
Checking a conversion before it counts
In our view, run Tag Assistant every time you add or change a conversion. Submit your own form or tap your WhatsApp button while it is connected, and check that the conversion event fires once.
Our Google Ads conversion tracking guide explains how to set up the conversion actions you are checking.
Before you trust your tags
- Tag Assistant connects to your home page and to the page that holds your form.
- Every page you expect to be tagged shows up as tagged in the Tag coverage summary.
- Your form sends its conversion event once, not twice.
- Your WhatsApp or call button sends its event when you tap it.
- The events you see in Tag Assistant also reach DebugView.
- Nothing fires before the visitor’s consent choice allows it.
RememberTag Assistant shows what your tags send while you browse your own site, and it stays hidden from your regular visitors. Connect it after every change, test the actions that count as leads, and install the Chrome extension for iframes and new tabs.
Our Google Ads management sets up Google Ads conversions and GA4 on your site, for forms and WhatsApp taps. We test each one before launch.
Questions about Google Tag Assistant
Can my visitors see the Tag Assistant debug window?
No. Google says debug information isn’t visible to your regular website visitors. The debug window stays open while you move around the same domain, as long as the Google tag is on the page.
Do I need the Tag Assistant Chrome extension?
Google recommends installing it, and a tag inside an iframe can only be debugged with it. The extension also follows pop-up windows and new tabs, and opens the debug window in a new tab instead of a pop-up.
What happened to Tag Assistant Legacy and Tag Assistant Companion?
Google combined both Chrome extensions into one Tag Assistant extension. If you use Legacy, you don’t need to uninstall anything, since it updates itself. Companion is uninstalled automatically once the new extension is updated.
Why won’t Tag Assistant connect to my site?
The page may not have the Google tag, the debug parameter may change how the page behaves, or the tag may load too late. Ad blockers, consent tools, several redirects, AMP pages and tags inside an iframe can also stop it.
Does Tag Assistant work with GA4 DebugView?
Yes. When Tag Assistant connects to your site, it adds a debug parameter, _dbg, to the end of your URL. Google says that parameter helps you view the events in other debugging tools, such as DebugView in Google Analytics.
Sources
Read on November 9, 2026. From Google’s Tag Assistant Help: Troubleshoot with Tag Assistant. From Google’s Tag Manager Help: Preview and debug containers.