UTM Parameter aus URL entfernen

cleanUtmFromURL.js

function() {
	// Callback für Google Analytics zum Entfernen der utm/ Kampagnenparameter
	return function() {
		if (!window.history.replaceState) { return; }; 
		var cleanSearch = window.location.search
			.replace(/utm_[^&]+&?/g, '') // utm Parameter werden aus der URL entfernt
			.replace(/&$/, '')  // entfernt ein überflüssiges & am Ende
			.replace(/^\?$/, '')  // entfernt ein überflüssiges Fragezeichen am Ende
			;
		
		// für den Fall, dass Fragments als utm Parameter eingesetzt werden
		var cleanHash = window.location.hash
			.replace(/utm_[^&]+&?/g, '') // entfernt die utm-Fragmente
			.replace(/&$/, '')  // entfernt ein überflüssiges & am Ende
			.replace(/^\#$/, '')  // entfernt ein überflüssiges # am Ende
			;
		window.history.replaceState({}, '', window.location.pathname + cleanSearch + cleanHash);
	}
}

Hey Michael,

thank you for sharing this code adaption from wistia's fresh url script with the world. I used it in the past two years but the last days made a deep analysis of single customer journeys necessary. And with what I found I really must admit that this callback function leads to non-persistent sessions in Google Analytics and Facebook Pixel.

⚠️ It should not be used on a production site ⚠️

I cannot determine where the problem exactly lies but here is what I found out:

A great amount of client journeys start as intended with all the information from the UTM parameters in their first Google Analytics hit. Then after a few! seconds later they click to the next page sending a new hit to Google Analytics. But this second hit is sent within a new session without any session information from the first one. This leaded to a lot of Sessions and Conversions with '(not set)' in the campaign, source, medium, term & content dimensions.

Google Ads is not affected by this because they store cookies in order to make sessions persistent. There are even tutorials out there to leverage this behaviour with all campaigns coming in with decorated URLs: https://www.simoahava.com/analytics/persist-campaign-data-landing-page/

But i really can't recommend this function anymore.

Best,
Norman