What is Conversion Linker in Google Tag Manager?

Updated: April 1st, 2025

In the past, advertising, targeting, and understanding ad effectiveness heavily relied on third-party cookies. However, prompted by heightened privacy concerns, many browsers have implemented or are in the process of imposing stricter controls on the usage of first- and third-party cookies, which were critical for Google Ads conversion tracking.

Starting January 4, 2023, Google Chrome is the latest browser to begin implementing restrictions towards third-party cookies. Apple Safari has been blocking third-party cookies for quite some time, and their restrictions for first-party cookies got even stronger in recent years with ITP.

Curious about how you can maintain the advantage in understanding the impact of ads on your business? While there is no perfect solution, one option is to preserve Google Ad click data in a first-party cookie to correctly attribute conversions (although limiting in the case of Safari, it’s better than having no cookies).

Of course, there are newer tools, such as enhanced conversions (sending hashed emails and similar data to Google). But combining both things (cookies and hashed data) will bring even better results.

In this article, we will discuss two options for creating a first-party cookie for conversion tracking, including the Conversion Linker Tag in Google Tag Manager!

Table of Contents

Here’s what you will learn in this article

• Why is this a problem?
• What are the possible solutions?
  • Conversion Linker Tag in Google Tag Manager
• How do you set up a Conversion Linker Tag in GTM?
  • Conversion Linker Tag for server-side
• Optional: Additional Configuration
  • Enable linking on all page URLs
  • Enable linking across domains
  • Override cookie settings (Advanced)
• Final Words

Video tutorial

If you prefer video content, here’s a tutorial from my Youtube channel.

Why is this a problem?

Advertising without assessing its effectiveness is like sailing into the sea without a compass – you might be moving, but you lack insights into whether you’re heading in the right direction.

Google Ads uses third-party cookies to improve ads through targeted advertising based on content users have viewed and the ability to see what happens after a visitor interacts with an ad – such as product views, purchases or email sign-ups. However, the death of third-party cookies is imminent.

In Google Ads, you can set conversions, which are actions (that you deem valuable to your business) taken after a user has interacted with your ad. Conversions allow you to monitor which ads create the most visitor activity, which can help you decide how to allocate ad funds.

With the phase-out of third-party cookies as the go-to navigation tool for the digital advertising seas, our reliance now shifts towards maximizing first-party cookies. While companies are also imposing limitations on first-party cookies, they are still crucial to preserving Google Ad click data for conversion tracking in the time being.

What are the possible solutions?

To ensure ongoing conversion tracking, you must set up a site-wide tag to deploy a fresh first-party cookie on your domain. This cookie will maintain a unique identifier for a visitor or the ad click that led the visitor to your site to use for conversion tracking.

There are two options for how to do this in GA4:

1. If you don’t want to use Google Tag Manager (I see no reason why you would want to avoid GTM, but sure, I am biased here), the first option is to set up the Google tag for Google Ads conversion tracking.
   
   If you have an existing Google tag on each site page, you can adapt the existing code to send data to your Google Ads account. You just need to replace the “TAG_ID” on the highlighted line with the ID provided when you set up your conversion tracking tags.
   
   Google believes the new Google tag provides a “unified tagging experience” since multiple Google products, like Google Analytics 4, can use it. When you create a website conversion action in Google Ads, you will be prompted with a Google Tag, which you need to install on every page of your website. Additionally, you must add an event snippet or a phone snippet to work with the Google Tag to track conversions. Read more about this method here.
2. If you have tracking set up using Google Tag Manager, you can create the Conversion Linker Tag – a pre-configured tag in GTM that stores ad click information in a first-party cookie. This method will be the main focus of the remainder of this tutorial.

Note: Google Analytics 4 will no longer preserve the GCLID in a cookie for Google Ads conversion tracking events, so you must use one of the methods above, as it is no longer sufficient just to link your Google Analytics and Google Ads accounts.

If you’re in a hurry, below is a brief flow chart to help you understand if you need to use a conversion linker in web tracking implementation. Start from the blue diamond.

Conversion Linker Tag in Google Tag Manager

When a person clicks on your ad, the URL will contain the Google Click ID (GCLID), and the browser could store this as a third-party Google Ads cookie.

Provided that a visitor completes an action you’ve defined as a conversion, the Google Ads conversion tracking tag is triggered. Then, the conversion is associated with the initial ad click that brought the visitor to your site.

With the restrictions and the removal of third-party cookies, this is a problem for us. You can no longer rely on the third-party Google Ads cookie to collect this information.

If you have tracking set up with Google Tag Manager, then the Conversion Linker Tag is the solution. This tag stores ad click information in a first-party cookie on your domain, providing Google Ads with the means to measure conversions after a visitor clicks on an ad to your site.

Update: Right now, Google is pushing Google Ads users to also install the Google Tag with the AW- id and fire it before any Google Ads conversion tag fires. When I follow this recommendation, I am no longer asked by the Google Tag Manager interface to create a Conversion Linker (which implies that it’s no longer necessary in this situation).

Nevertheless, if you have Google Tag (with AW- ID) and Conversion Linker, this will not cause any serious problems.

How do you set up a Conversion Linker Tag in Google Tag Manager?

Setting up the Conversion Linker Tag in Google Tag Manager is simple. In GTM, go to Tags in the left-hand navigation and click “New”.

Set the tag type to the pre-configured “Conversion Linker”.

Set the triggering to be on the pre-defined “All Pages” trigger.

Name and save the tag. Save and publish the container once you have confirmed that the tag is working in Preview & Debugview.

That’s all!

Note: it’s also important to configure the Google Consent mode if you use Google Ads in the EEA (European Economic Area). I talk more about this in my Google Tag Manager course for Beginners.

Conversion Linker Tag for server-side

If you are using server-side, you can follow the same steps as above in your server-side container to create the Conversion Linker Tag. This article further explains how to set Google ads conversions on the server-side using Google Tag Manager and Google Analytics 4. I also talk about this in my intermediate/advanced Google Tag Manager course.

If you choose this path, then remove any equivalent Ads conversion tracking tags from the web container to avoid data duplication.

Optional: Additional Configuration in Conversion Linker

For many people, the Conversion Linker tag will not require any further configuration.

Enable linking on all page URLs

By default, once a user has reached your website through an ad click, the Conversion Linker tag only captures page information on the landing page. If you enable linking on all page URLs, the conversion linker will preserve the Google Click ID parameter in the page URL as the visitor continues browsing the site. This is useful in cases where the visitor lands on your site (does not interact with the cookie consent banner) and then gives consent on one of the subsequent pages. If you fire the conversion linker tag only after consent is given, the tag will be able to take the click ID from the URL.

Enable linking across domains

Should your website extend over multiple domains, then you may consider enabling linking across domains. This is helpful when you have landing and conversion pages across various domains.

The Conversion Linker tag will adda parameter to the URLs of links and forms the redirect the visitor from one domain to another. As a result, the cookie (that stores the Google click ID) will be the same across different subdomains

Once you click “Enable linking across domains”, you will need to enter all the domains that are involved in the user journey, e.g., website1.com,website2.com. Separate all domains with a comma.

Override cookie settings (Advanced)

Some situations that may warrant overriding the cookie setting are:

• you already have cookies with the same names (_gcl_aw and _gcl_dc),
• you need multiple sets of cookies
• you don’t want ad click info from one subdomain of your website to be available for conversions on another subdomain

But for most companies, these settings are not needed. Hence the word “Advanced”.

When you click “Override cookie settings”, you can set three fields: name, domain, and path.

• The name is the prefix used on the cookie name. The default prefix for the cookie names is _gcl. Let’s say you updated the prefix to be _gcl2, then the names of the cookies set by the Conversion Linker tag will be _gcl2_aw & _gcl2_dw.
  • Note: Ensure that when modifying the name of the cookies, you actively configure tags, such as Google Ads conversion tags, to use the updated prefix.
• The domain refers to your site’s domain where the first-party cookie is set. By default, the Conversion Linker tag sets cookies on the highest-level domain. For example, if your site is shop.yourdomain.com, the tag will set the cookie on yourdomain.com. Only adjust this field if you need to confine cookies to a lower-level domain, like shop.yourdomain.com.
• The path is the path used to set the cookies. The cookie path will default to the root level (/). You should only adjust this field if you need to limit cookies to a domain subdirectory, such as yourdomain.com/clothing.

Read more about additional configurations here.

Conversion Linker in GTM: Final Words

First-party cookies have emerged as the unsung heroes of Google Ads conversion tracking, boosting the accuracy of ad conversion tracking. Although companies are imposing further restrictions on first-party cookies, having something is better than having absolutely nothing, right?

If you have implemented Google Ads tracking with Google Tag Manager, you need to add the Conversion Linker Tag to your GTM container to ensure you’re not sailing into the dark with your ads (for both client and server-side tagging).

Alternatively, you can implement a new Google tag or alter an existing Google tag for Google ads conversion tracking.

It is no longer sufficient just to link your Google Analytics and Google Ads accounts, so you must implement one of the two methods mentioned above.

Despite the ever-changing landscape of technology, ads can still be an effective approach to increasing visitor activity to your site. We just have to learn how to travel through the shifting currents.

Speaking of the future of Google Ads conversion tracking, Google is betting a lot on collecting hashed user data (like an email address or first name) that can be sent together with the conversion to Google. This is a part of Enhanced Conversions. I talk more about them in my Google Tag Manager courses.

The GTM course for beginners shows the client-side setup of enhanced conversions, while the intermediate/advanced GTM course explains the server-side setup.