August 24, 2018

What is Conversion Linker in Google Tag Manager?

Updated: August 24, 2018. In June 2017, Apple announced Intelligent Tracking Prevention (ITP), an initiative aimed at limiting third-party trackers from capturing cross-site browsing data and it will be launched really soon (or maybe it already is? Honestly, I’ve lost the track). This might become a problem for those who are using Google Ads (previously known as Google Adwords) because the ITP will block cookies which are an essential part of G Ads Conversion Tracking.

In response, Google introduced several ways how to decrease the impact of the Intelligent Tracking Prevention. Conversion Linker Tag is one of those solutions. Do you need it? Everything is explained in this blog post.

 

What is Intelligent Tracking Prevention?

In short, with ITP, third-party cookies that are determined to be able to track users across sites can only be used for 24 hours from the time a user visits a website via Safari. After 24 hours, the third-party cookies can only be used for log-in purposes. The cookies are purged entirely after 30 days.

Intelligent Tracking Prevention - Explanation

Why is that important? Google Ads uses 3rd-party cookies for conversion tracking, therefore, ITP will break it and all conversions that happen after 24 hours from the time a user lands on your page will not be tracked.

 

What are the possible solutions?

Actually, there are three options (according to Google’s official knowledge base), choose one:

  1. You can link GA with Google Ads (if you haven’t already) and you’re good to go. Google Analytics uses 1st party cookies and shares the data with G Ads, thus your conversion tracking will continue working properly.
  2. If you have new websites you wish to track and you do not want to use Google Tag Manager (I see no reasons why would want to you avoid GTM 🙂 ), start using the new Global Site Tag (gtag.js). Recently, Google announced this tracking method with the intention to streamline tracking across Google products, including their “measurement, conversion tracking, and remarketing products.” For now, Google Analytics, Google Ads and, in the future, other Google Products will use tracking codes of the same structure and technology behind it. Go ahead to Google Analytics or G Ads Conversion’s settings and you’ll see that they are already recommending gtag.js (see the example below)
    gtag.js tracking code
  3. If you’ve installed G Ads Conversion Tracking via Google Tag Manager AND haven’t linked it to Google Analytics (well, maybe you use another analytics tool), start using Conversion Linker Tag. In this blog post, I’ll explain how to set it up.

Update: since some of my readers are still in doubt whether the information that I provide here is accurate, here’s a tweet from Brian Kuhn who is one of the main people behind GTM.

What is Conversion Linker Tag in Google Tag Manager?

When people click on your ads, the URL of the landing page (of your website) typically contains ?gclid=xxxxxxxx. This ID is saved as the 3rd party Google Ads cookie.

When a site visitor takes an important action that you’ve tagged as a conversion, a Google Ads conversion tracking tag is fired. As a result, the ad click information (gclid) is used to associate that conversion with the ad click that brought the visitor to your site.

Once the ITP goes live, that Google Ads 3rd party cookie will be functional only for 24 hours after a visitors visits your site. The solution? Conversion Linker Tag!

This tag automatically detects the ad click information in your landing page URLs, and stores this information in 1st party cookies on your domain (instead of 3rd party cookie), meaning that ITP will no longer affect the Google Ads conversion tracking and you’ll be able to measure important conversions even after 24 hours after a visitor lands on your page.

 

How to set up Conversion Linker Tag In GTM?

Luckily, it’s really easy.

  • In Google Tag Manager, go to Tags.
  • Choose Conversion Linker as a Tag Type.
    Conversion linker tag in Google Tag Manager
  • And set it to fire on All Pages. No other configuration is necessary.
    Conversion Linker Tag Configuration

Done! Publish the updated Google Tag Manager to live environment. Before that, don’t forget to test the tag with Preview and Debug mode.

 

Optional: Additional Configuration in Conversion Linker (Advanced)

By default, the Conversion Linker tag sets ad click information in cookies named _gcl_aw and _gcl_dc using the top-most domain and root level path. And that sufficient for this tag to work. But if you need to override any of its settings, you can do so in the Linker Options.

You should only adjust the settings if you have a specific need that requires it and you really know what you’re doing. For example, you may need to override some cookie settings if you:

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

When you select the Override cookie settings option, fields for Name, Domain, and Path will appear:

  • Name: This is the prefix used as part of the cookie names. The default prefix name is _gcl. For example, if you change the Name to _gcl2, the Conversion Linker tag will set cookies named _gcl2_aw and _gcl2_dc.
    • Important: If you change the prefix of the cookie names, any tags that read ad click info from these cookies (e.g. G Ads conversion tracking tags) must also be configured to use the same prefix.
  • Domain: This is the domain of your website on which the first-party cookies should be set. By default, the Conversion Linker tag will use the highest level domain on which it can set cookies. For example, if your website address is support.yourdomain.com, the Conversion Linker tag will set the cookie domain to yourdomain.com. Only set this field if you need to limit the cookies to a lower-level domain, e.g. only for support.yourdomain.com
  • Path: This is the path used to set the cookies. By default, the cookie path will be the root level (/). Only set this field if you need to limit the cookies to a subdirectory of a domain, e.g. only for yourdomain.com/posts.

 

TL;DR: Do you need to use Conversion Linker?

If you’re in a hurry, here’s a brief flow chart which will help you understand whether you need to use conversion linker in web tracking implementation. Start from the blue diamond.

Should you use Conversion Linker

However, if you’re still not sure whether to add the Conversion Linker, go ahead and implement it. It will not break things. So if you want to be extra-cautious, add it to your container. After seeing mass confusion in the industry related to CL (especially when someone mentioned that Google’s support told him to add the CL even when it is not necessary), at some point, I even started to question my own beliefs regarding this topic. Thus I decided to contact Simo Ahava and got a confirmation that Conversion Linker works exactly as I understand it.

 

Conversion Linker: Final Words

If you’re tracking Google Ads conversions with Google Tag Manager, you need to start using Conversion Linker Tag as well. In June 2017, Apple introduced a solution which will seriously limit 3rd party tracking cookies and (surprise!) G Ads cookies are one of them.

In order to keep tracking important events with Google Ads precisely, you need to start using Conversion Linker tag as well.

You do not need this tag if you:

  • Have linked Google Analytics account to Google Ads.
  • Or you are tracking Google Ads conversions by using the new Global Site Tag (gtag.js).

However, if after reading this blog post you’re still not sure whether you need to add Conversion Linker to your GTM container, go ahead and add it. It won’t break things or do any harm.

Julius Fedorovicius
In Google Tag Manager Tips
49 COMMENTS
Mike
Thank you Julius Can you please explain why there is a difference if adwrods and GA are hard coded to the site or if both are implanted using GTM ? Why does it make a difference ? Thank you
    Julius Fed
    The result is the same, but the implementation method differs. When you asked me this question, I now understand that I need to update the scheme in this blog post because it's a bit confusing. Basically, you can either connect GA and Adwords or create Conversion Linker tag. Not sure how Adwords will react if both options are completed, though...
Mike
Thank you for the clarification. So just making sure, as long as adwords and GA are linked there is no difference if it was implanted using GTM or hard coded to the website ? "If you (or your developers) have hardcoded Google Analytics and Adwords tracking codes to a website (not via Google Tag Manager)" This is the sentence that got me confused
    Julius Fed
    Yes, it should work fine (at least, Google says so).
Marcin Miłowski
Great explanation thanks for TL;DR version :D
List
Nice Explanation
Lenka
Hello there, great article. But still I am not sure if I understand - we use GTM for both Google Analytics and Adwords. We do not use global site tag yet. Adwords and Google Analytics are linked together - but no metrics are imported. Should we use a Conversion linker? Thank you - Lenka
    Julius Fed
    Hey, you should not use Conversion Linker because you have already linked Ga with Adwords. It's strange that data is not visible yet. I recommend contacting Adwords support for more details.
JanB
Imagine the following case: - AdWords landing page on domain1.com - Conversion happens on domain2.com - GTM on both domains - GTM contains Analytics tag with proper cross-domain tracking - GTM contains AdWords conversion linker tag - GTM contains AdWords conversion tag on domain2.com's thank-you page Imagine you want to track conversions in AdWords as an imported Analytics goal AND with the adwords conversion tag. The conversion linker tag will not work, because you can not set multiple domains in the domain settings. So we can basically stop using double-conversion tracking (with GA and AW), as AW's conversion linker doesn't have cross-domain functionality.
    Julius Fed
    Hey, in this case, you will be able to track conversions only with help of GA (linked to AW). No need for conversion linker here. Since GA is properly configured for cross-domain tracking, goal completions will be tracked and then automatically imported to AW. Unfortunately, I believe that Adwords conversion tag with Conversion Linker will not work (just as you have mentioned) because of cross-domain tracking stuff. Unless, I don't know something. Honestly, in situations like yours, I track conversions only with GA goals (linked to AW). Does that make sense to you?
      Catalina Stingaciu
      Hi, Thanks for the article. I have the same case mentioned above and I'm a bit confused. In this case, does it even make sense to place the adwords conversion tag on thank you pages through GTM? Or should I just not place it at all since we can import the Goals? Thanks!
        Julius Fed (Fedorovicius)
        Hey, here's the answer to your question https://www.lunametrics.com/blog/2016/02/03/difference-adwords-conversion-tag-import-analytics-goals/ TL;DR: Reports of Adwords conversion tag AND Imported GA goals will be different because of different attribution models. Therefore I still recommend using Adwords conversion tag and thus have two different sets of data: - Conversion data in GA - Conversion data in Adw.
          Catalina Stingaciu
          • Jun 12 2018
          Awesome, thanks so much for your answer!
    Arnab Sen
    If you are using GTM to fire the adwords conversion code, then you need to use the conversion linker, doesn't matter if you linked GA with adwords or not. If you are tracking the same thing with GA and importing the goal to adwords , then no point having the adwords conversion code, also because it will cause confusion, because there will be data discrepancy
      Julius Fedorovicius
      I'm no ore concentrated and I take back my previous comment:) so, unfortunately, your comment isn't right. Even though in Google's support page it's written that if you use Google Ads via GTM (see option 2), you need CL, the option #3 states that if you have linked Google Ads with Google Analytics, the G Ads conversion tag reads GA's cookie and still tracks conversions properly, therefore, no conversion linker is needed. So in other words, my scheme (in this blog post) is still valid.
Ducret
What about other conversion script : facebook, bing ags, Adroll, ? Must we use conversion linker for these platform ?
    Julius Fed
    Conversion Linker works only with Adwords. Honestly, I'm not sure what to do with Facebook, Bing ads, etc. I believe they should do some changes on their side separately but I don't want to say anything false.
tania
Hi Julius, Thanks for a great post! What happens if you have your Adwords and GA linked AND you use the conversion linker tag as well?
    Julius
    Interesting question. As far as I know, nothing bad :)
Dan
Thank you Julius for your article. I am trying to understand if in GTM the conversion linker tag is in addition to the existing Adwords conversion tag or in replacement. In other words, do we need to remove any Google Ads tags that were there before we added the conversion linker?
    Julius Fedorovicius
    Hey Dan. Conversion Linker is an addition to Google Ads tags. It does not replace them. Therefore you don't need to remove G ads tags.
Joao Matos
Hi Julius, Is it still necessary to use Conversion Linker Tag, if I'm tracking Google Ads conversions by using the new Global Site Tag (gtag.js) via GTM? Thanks!
    Julius
    No, the workflow diagram in this blog post explains that :)
      Joao Matos
      Sorry, did not understood it. But Thanks, anyway.
Arjan
Hey Julius, I always prefer to link Google Ads and Analytics instead of the conversion linker. Especially to make use of Remarketing, as Analytics gives you much more options to make audiences. But how do I set this up correctly with the GDPR in mind. I use OneTrust, thanks for the great implementing guide (!!!!). If people don't accept marketing cookies, but do accept statistics cookies, Google Analytics will stil push information to AdWords, which is (i guess) not allowed. So do I have to use the conversion linker in that case?
    Julius Fedorovicius
    That is not a problem. When you connect GA with Google Ads, visitors data is not shared on every pageview. Here's how it works: - User lands on a page (and the gclid parameter is in the URL) - That parameter is stored in GA cookie (but the data is not sent yet anywhere). - When a conversion tag fires, then that GA cookie is read and gclid is fetched. So no conversion tag fires, no problems with GDPR because no data will be sent to Adwords. At least, as far as I know.
Rebecca
Hi Julius, thanks for this article, I have learnt a lot from it! I have a question: my GA is already linked to Google Ads AND I have implemented Conversion Linker. Does that matter? Can I have both? Will it affect the data in any way? Thanks! Rebecca
    Julius Fedorovicius
    Honestly, I'm not sure. I'd say that's nothing wrong but personally if I were you, I'd remove Conversion Linker since GA is linked to G Ads.
      Rebecca
      Thank you Julius! I will investigate more.
James
Hi, My question is: 1) If i have a website where i already have some Google Ads campaigns going on with the use of Google Analytics, and there are a few of them (few Google Ads accounts are connected), and there is this agency who wants to promote content with the use of DCM (they told me to add the conversion linker tag and fire it at all pages and also add some floodlight conversion counters) and im a little bit worried that it will brake the normal Google Ads campaigns. Should i worry about it? 2) If I apply conversion linker tag and those floodlights conversion tags should i update my cookie policy because of that? Thank You !
    Julius Fedorovicius
    Sorry, I have no experience with Floodlight tags, therefore I do not want to misguide you.
      Julius Fedorovicius
      1. According to Google's documentation, Conversion Linker is needed for Floodlight tags as well. However, I haven't used them in the same project together with Google Ads tags, therefore I cannot give you any advice here. 2. Your cookie policy already had to be updated due to Google Ads tags. However, you should mention Floodlight tags there too.
James
No, we do all the promoting with the use of GA (Remarketing lists, Goals) so we dont even mention it in the policy. Well, i need to discuss that with someone if promoting content even without additional (AdWords now GAds) tags requires having them listed in the cookie policy. I'm also curious if adding this conversion linkers having those Google Ads accounts connected and running campaigns will brake them somehow. Thank You.
Asif
To Setup Goals with event or Destination it is easy to use Tag Manager. No need to add codes individually again and again to the pages. But, if Google recommends to use gtag.js then it is hard to setup event tracking Goals in Analytics which we could import to Google Ads for conversion tracking.
    Julius
    Gtag.js is recommended if you plan to hardcode it. However, if you plan to use GTM, no need to implement gtag.js.
      Asif
      Thanks Julius.
Reece
I'm still confused. The text says that if we track google conversions through GTM - but HAVE linked GA to AW's - then we don't need the conversion linker tag installed. But then in the 'final words' section you say: "If you’re tracking Google Ads conversions with Google Tag Manager, you need to start using Conversion Linker Tag as well. In June 2017, Apple introduced a solution which will seriously limit 3rd party tracking cookies and (surprise!) G Ads cookies are one of them." - So we DO need the tag installed?
    Julius Fedorovicius
    You don't need if GA is linked to Google Ads. I'll update that sentence to get rid of confusion :)
      arnab
      Even if you have GA and Adwords linked, still conversion linker is required , if the setup is through GTM
        Reece
        That's what I was under the impression of - and what our Google team instructed us to do also. @julius - can you clarify?
          Julius Fedorovicius
          • Oct 2 2018
          Google Team instructed? That's strange. I'll need to dig deeper then and clarify this.
        Julius Fedorovicius
        No, it's not. When GA is linked to G ads, gclid is stored in the 1st party Google Analytics cookie and when the conversion is completed, G ads use that information from the GA cookie. Source
          arnab
          • Oct 2 2018
          Thank you for the source, if you read that carefully enough, it talks about side wide tagging, if you have Gtag codes on the website, you don't need conversion linker. But suppose you setup adwords conversion code using GTM and no Gtag.js codes are there on the website, conversion linker is mandatory even if you have the GA and Analytics linked. If you are talking about e-commerce tracking setup in analytics and looking at conversions for that conversion linker is not necessary. I hope that clears the doubt for all.
Reece
ok - and we've followed option 2 on that list of 3 options. Is that as good as using option 3? Should we just leave the conversion linker tag firing as it is? Also - we use DDA tracking and I notice that a negative of the GA only solution is: "Note that the Google Analytics cookie only stores the GCLID for the last click." - so this solution will not be able to track multiple clicks for conversions, such as if customers are using DDA or cross account conversion tracking - and therefor *should* use the conversion linker through GTM? Thanks Julius!
    Julius Fedorovicius
    Yes, in that case, use Conversion Linker.
arnab
Thank you for the source, if you read that carefully enough, it talks about side wide tagging, if you have Gtag codes on the website, you don't need conversion linker. But suppose you setup adwords conversion code using GTM and no Gtag.js codes are there on the website, conversion linker is mandatory even if you have the GA and Analytics linked. If you are talking about e-commerce tracking setup in analytics and looking at conversions for that conversion linker is not necessary. I hope that clears the doubt for all.
    Julius Fedorovicius
    I understand that people will not simply believe me just "because I say it" but maybe Simo Ahava will change your mind. I just had a quick chat with him and he confirmed what I was saying + what that previous link I shared is stating. To quote him: "If you have GA and GAds linked (in GA’s property settings), then GAds will import the conversions from GA and no Conversion Linker is needed. If you run GA via GTM or gtag on the site, then the gclid will be stored automatically in the _gac cookie, so no Conversion Linker should be needed. Conversion Linker would only be needed if 1) there’s no GA running on the site and you haven’t linked GAds and GA, or 2) if you want more control over how the linker works (e.g. custom cookie settings)." However, I can add to Reece's previous comment, since she is planning to use (supposedly) multiple G ads accounts to drive traffic, then she should use Conversion Linker. To sum up (and I will have to update the post accordingly): There is no negative side-effect of having Conversion Linker anyways. So a good precaution would be to use it. However, you DON'T have to do that if you have linked GA with G ads and GA is implemented on a website (via GTM or gtag.js).
Reece
Where does DDA tracking fit into that as I confirmed above that the GCLID only stores data for the last click? Also - I most definitely am using multiple accounts to drive traffic to the same domain, as many advertisers are - but thanks for the clarifications.
Duncan Newbury
Very helpful, thanks.

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