What Is The Difference Between Source & Medium In Google Analytics?

Source and Medium in Google Analytics are terms that even the best digital marketers get mixed up sometimes. Google’s support and guidelines are, as normal, a bit washy and wordy, so we thought we’d try to explain it simply.

Source vs Medium in Google Analytics

Source is where your website’s traffic comes from (individual websites, Google, Facebook etc).
Medium is how it got there (organic traffic, paid traffic, referral etc).

People like analogies (apparently), so here’s one:

  • Think of a journey. The Source would be where you came from, the Medium, is the method of Transport.


  • The Source would be the train station, the Medium would be a train (now the above image makes sense)

Before we break it down further, I’m going to add another definition into the mix… Channel. We’ve written an article on ‘What are Channels in Google Analytics & How to Change Them?’, so have a read of that if you want to know more, but essentially Channels are named groupings of Source & Medium.

So, now you’ve had the simple explanation of what Source and Medium are, let’s go into them further.

What is Source in Google Analytics

The Source in Google Analytics is where your website’s traffic comes from, or as Google says, it’s the origin of your traffic. Your traffic has to come from somewhere, whether that’s people visiting your site from search engines, or from a social media site or some another website. It comes from somewhere, and this is what the source is – what site the traffic came from.  When it doesn’t come from a website, or there is no data on the original website, the source is known as Direct. This would be when someone typed your URL into a browser, clicked a bookmark or came from an offline tool or document on your computer (if tracking has not been set up). If it’s not direct, it should be the name of a site.

What is Medium in Google Analytics

Medium is how your website’s traffic arrived at your site. Google calls it the general category of the source. So, for example, the Source of your traffic might be Google, but the Medium could be Organic, CPC, Display or Referral

There are some core categories within Medium:

  • Organic Traffic (non-paid traffic from search engines)
  • CPC/PPC (paid traffic from search engines)
  • Referral (a link from another website)
  • Email (link from an online email tool such as Hotmail or Gmail)
  • Social (link from a social media site)
  • None (direct traffic)

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Can you create your own Source and Medium?

You can create your own Source and Medium by adding parameters to some of the links arriving at your site which will override the existing Source/Medium. This isn’t possible to do it on all links. So Organic links from Google will always be Source = Google, Medium = Organic. However, if for instance, you have an email campaign that includes links to your site, normally this would either be shown as:

  • Source = Gmail, Medium = Email
  • Source = Direct, Medium = (none)
  • Source = Hotmail, Medium = Email

This doesn’t tell you that the source was actually your Newsletter.

So, in this case, you would build a Campaign URL which creates a parameter at the end of your URL which changes the Source/Medium in Google Analytics. You can do this at https://ga-dev-tools.appspot.com/campaign-url-builder/. It’s a really simple tool where you enter in your URL, tell it what the Source and Medium should be, and it will give you the URL to use. You can even add Campaign Name, Campaign Term and Campaign Content.

The above will generate the URL https://www.yoursite.com/?utm_source=newsletter&utm_medium=email&utm_campaign=August-Newsletter-2019

When this link is clicked, it will change the Source/Medium in Google Analytics

Again, you won’t be able to use this on all traffic coming into the site, only the URLs that you control people clicking on, i.e. not organic traffic, not naturally earned links etc.

One note about this tool. Source and Medium are case sensitive, so be careful; ‘newsletter’, ‘Newsletter’ and ‘NewsLetter’ would be classed as different sources.

Can we help you?

We hope you’ve found this article useful, and if you would like to find out about Channels in Google Analytics, please read this article. Propellernet offers Google Analytics training, so if you would like to learn more face to face, please contact us. If you are concerned that your Google Analytics account, we can perform a full Google Analytics Audit or for anything else, checkout our range of Analytics Services

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