What The Gclid?

By Stephanie White | @stephanieppcpro | Account Manager at Hanapin Marketing

Most of us are aware of AdWords auto-tagging but don’t know how it works. What does auto-tagging do and why is it important in your AdWords account?  Auto-tagging is a way for AdWords to communicate all the details about a user session to Analytics.  In turn, we are able to use the information reported in Analytics to measure post-click behavior.


Auto-tagging is a setting in AdWords that allows the system to append your final URLs with parameters in order to report statistics into Analytics. Auto-tagging is a huge time-saver, but sometimes it breaks, creating a real challenge when trying to measure your ROAS. Plus, whenever data is reporting inaccurately in Analytics, a considerable amount of time can be spent troubleshooting performance issues. Or worse, it can make you think your paid search traffic is not converting.


You’ll notice with auto-tagging that Google appends “Gclid” to your final URLs. What does this term mean anyway? The term “Gclid,” or as it makes more sense to think of as a ‘Google Click ID’ is a way for AdWords to communicate information about the searcher to Analytics. This data allows you to view post click activity in Analytics, such as time spent on site, pages per visit, etc. AdWords auto-tagging will encrypt Protocol Buffers into the URL to report on information like:


  • Source
  • Medium
  • Campaign
  • Ad Group
  • Keyword
  • Match type
  • Ad Creative


When you enable auto-tagging in AdWords you do not have to manually set-up tags for every URL. Whenever possible it is recommended to use auto-tagging over manual tagging to avoid mistakes. Plus, manually tagging each URL can be time-consuming and things like case sensitivity come into play because it will report capitalization sources separately.


First, check in AdWords to see if you have auto-tagging enabled. You can do this under “Account Settings > Preferences > Tracking > Auto-tagging > Yes.”


adwords auto tagging
Turn auto-tagging on


In these example tagged URLs, using capital vs. non-capital sources or mediums will cause Analytics to split up the data and report these as two independent statistics. This is another reason why auto-tagging is ideal over manual tagging.




Obviously, there are times when a client is unable to give us sufficient privileges to connect AdWords to Analytics and we do need to manually tag each URL to be able to view performance data. When you create manual tags, it is important to make sure they are identical and use the same case to make sure they appear under the same line item in Analytics.


Also, manual tagging is useful when you are advertising in other third-party platforms, such as Bing, Yahoo, Facebook, Twitter, etc. Including manually tagged tracking URLs will help you measure the paid traffic independently from the organic traffic.


Manual Tags And Reporting


Yes, case matters when you are manually tagging URLs for your campaigns. As mentioned above, you do not want Analytics splitting up your stats because you used capitalization on half of your URLs.


You will want to make sure the source, medium, and campaigns are all the same and using the same case. I usually prefer to capitalize my campaign because I like how it appears under “Acquisition > Campaigns > All Campaigns.” This setup is just a preference,but ensure they are identical or match what already exists in your account. Here’s an example.


  • Source: google
  • Medium: cpc
  • Campaign: CampaignName (or Campaign_Name)
  • Keywords


If you do use capitalization on some and not others the source/medium will report separately in Analytics. You could have 2 AdWords sources that show as such.


  • Google / cpc
  • google / cpc


Reasons Websites Drop The Gclid


Another issue we have found for the Gclid getting dropped is when the website has a URL that redirects. A website that redirects from http://www.website.com to http://website.com will drop the Gclid and you will have incorrect data reporting in Analytics. This even happens when a HTTP URL redirects to the secure HTTPS URL. Google has a help section entitled Check if AdWords auto-tagging works to help you ensure you are using the correct URL.


Third party payments options can also cause the Gclid to be dropped. On an ecommerce site, you may see a referral from Paypal.com in Analytics. Thus, if someone clicks your ad and pays via PayPal, the referrer will be PayPal instead of AdWords.


paypal.com referral
A referral from PayPal


Troubleshooting The Gclid Issue


Unfortunately, auto-tagging settings and Gclid dropping off is one of the most overlooked issues with AdWords. If you have a high volume of ads it can be tricky to make sure these are set-up properly. Every website is different, some use WWW and some do not, other websites use HTTPS and some do not. In order for auto-tagging to work properly, you will need to make sure the AdWords final URL and the website URLs match up.


In one case, we had a client who had all the ads pointed to http://www.website.com instead of the https:// version. Display traffic was reporting terrible metrics when it was really the URL issue causing the Gclid to drop. Since we corrected the final URL, Display is one of the best performing campaigns.


In another case, some of the URLs were set up with the WWW and some were not, preventing Analytics from reporting revenue associated with Paid Search. Analytics was reporting most transactions as direct.


Checking The Gclid In Analytics


So how do you know if you have a mismatch or if you have an issue with Gclid parameters? Analytics is a good place to start.  You might see a notification error that says ‘Invalid AdWords gclid’ that will give you additional details into what is happening.


Invalid AdWords gclid
Invalid AdWords gclid


Analytics may also show you a notification error stating there are clicks and sessions discrepancies.


Clicks and Sessions Discrepancies
Traffic discrepancies


You can also view the clicks vs sessions data under “Acquisition > Adwords > Campaigns.”


google analytics adwords clicks sessions
AdWords metrics in Google Analytics


In the example above, you can see the clicks and sessions have a significant discrepancy in their data. Keep in mind, these numbers will never match up exactly, but there shouldn’t be this big of a difference in the data.


Another place to check is under “Conversions > Multi-Channel Funnels > Top Conversion Paths.”


assisted conversions paths
Multi-channel funnels


As you can see in the above example, many of our conversions are falling under direct traffic, which may be because the URL is dropping the Gclid.


Next, you can visit the Google support page. Open a new window in Chrome and select “Menu > More Tools > Developer Tools” and select the Network tag. In the address bar, set up your URL like the example provided and select enter http://www.example.com/?parameter=1&gclid=TeSter-123. After the page finishes loading, you should still see the Gclid in the address bar. If you do not that means your website is dropping the Gclid and auto-tagging will not work.


Also, keep in mind that when you add your website in the address bar and if you see a status of 302, this status means your website has a redirect and auto-tagging will not work.


google chrome redirect auto-tagging gclid
A 302 status


We hope this article will help you understand how auto-tagging actually functions, the differences between auto-tagging and manual tagging and how these features can impact your Analytics data. We have also included some additional resources below to help you verify if your auto-tagging is working and additional reasons why it may not be.