GA4 DebugView: How to Check Your Events Are Working

You set up a new event yesterday. You want to know if it works. So you open your reports and find nothing there, and now you are stuck wondering: is the event broken, or is Google just slow?

Usually it’s the second one. Standard GA4 reports can take a day to fill in. That delay is fine for reading history, and useless when you are trying to check your own work.

DebugView is the answer to that. It’s a screen inside GA4 that shows events landing as they happen, from your device only. You click a button on your site, and a second later you watch the event show up.

What the screen shows you

You’ll find it under Admin, in the Data display section. Three columns do the work.

The middle column is the one you watch. Each event appears as a bubble with the second it arrived. Click any bubble and it opens up to show the parameters that came with it — which is how you check that your purchase event really carried a value, and that the value was a number and not a string with a currency symbol stuck to it.

The left column groups the same events by minute, so you can scroll back a little way. The right column counts what has arrived in this session. Key events show up in green, which makes it easy to confirm that the action you marked as important is being counted as important.

Turning debug mode on

DebugView only shows events that carry a debug flag. Everything else goes into the normal pipeline and never appears on this screen. There are three ways to add the flag, and any one of them is enough.

The easiest is Google Tag Assistant. Open tagassistant.google.com, enter your site, and it loads your page in a window with debug mode switched on for you. If you use Google Tag Manager, its own preview mode does the same thing — and this is the combination most people should reach for, because Google’s documentation covers both routes.

If you install the tag directly with gtag.js, you can set the flag in code instead. Adding 'debug_mode':true to your config line turns it on for every event on the page. You can also add it to a single event if you only want to watch that one.

There is one detail here that catches people out. Setting the parameter to false does not turn debug mode off. To stop debugging you have to remove the parameter completely. Leave a 'debug_mode':false in your production code and you are still sending debug traffic.

When nothing shows up

An empty DebugView is normal for about ten seconds and a problem after a minute. A few things cause it.

• The wrong device is selected. The dropdown at the top right picks which debug device you are watching. If you have been testing on your phone and a colleague is testing on a laptop, you might be looking at their stream.
• Consent has not been given. If your site uses consent mode or a cookie banner, events are held back until the visitor agrees. On your own test visit, accept your own banner first.
• The event never fired. This is the useful failure. If Tag Manager’s preview shows the tag firing but DebugView stays empty, the problem sits between the tag and Google. If the tag is not firing either, the problem is your trigger, and DebugView cannot help with that.

That last distinction is what makes the two tools worth using together. Preview mode tells you the tag fired. DebugView tells you Google received it. A setup is only proven when both agree.

Try it on something you already have

Open Tag Assistant, load your site, and click through a page or two while DebugView is open in another tab. You should see page_view and scroll arrive within seconds. That confirms the plumbing works before you go anywhere near a custom event.

Then do the same for whatever you built most recently. If you are still setting up your first events, our guide to GA4 event tracking covers what to send in the first place, and the piece on key events explains which of them are worth marking.