Does duplicate tagging in GA4 matter?
I recently saw on LinkedIn that someone was asking about whether the Google Analytics 4 tag firing twice mattered or not.
Logic says that it should, but there is actually an option that says de-dupe, so you don't have to worry about it. It's ticked by default, so as long as you've not changed it, then it doesn't matter. You can just ignore it.
If the same Google tag is configured two or more times on the same page, it may cause duplicate data or mixed settings. This scenario can occur if you accidentally implement the same tag twice or if you combine two Google tags that were previously both installed on the same page. To ignore duplicate instances of on-page config commands, you can enable the corresponding option in the “Manage Google tag” section of the Admin tab: “Ignore duplicate instances of on-page configuration”. To prevent issues, this option will be enabled automatically when you combine two Google tags.
It is actually mainly though when people put on Tag Manager and don't remove it on the site.
There's absolutely nothing to worry about. It is best practice to remove the on-page one and have it all in Tag Manager. But it's no harm keeping it if everything's working.
The main thing is just the key events. Obviously, if purchases are doubling up, then you've got a problem. But for page views, Google Analytics usually automatically de-dupes anyway. But if not, it's quite easy to spot because all your page views are even numbers.
You'll know whether it's right or wrong because if your revenue is double what it should be, then yeah, it's wrong.
Ben Luong is a technical marketing consultant who operates where AI falls short. In a world flooded with cheap, mediocre code and automated strategies, he provides the expert integration, verification, and strategic accountability required to make modern marketing stacks profitable. He specialises in architecting Google Ads, SEO, and GA4 into a single, high-performance system that is accountable to the bottom line.
