What Mediums are Available in Google Analytics?
Understanding exactly how people find your website is fundamental to smart marketing. Google Analytics uses "Source" and "Medium" to tell this story. While "Source" explains where traffic came from (like Google or a specific newsletter), "Medium" tells you how it got there. This article explains what the various mediums in Google Analytics mean, why they matter, and how you can use them to get a clearer picture of your marketing performance.
What Exactly is a "Medium" in Google Analytics?
Think of the "Source" as the city a traveler came from (e.g., google.com, facebook.com, mail.google.com) and the "Medium" as the mode of transportation they used to get to your website (e.g., organic search, a social media post, an email link).
The medium is a broad category that buckets your traffic into understandable channels. It answers the question: "How did this user arrive on my site?" Looking at your traffic by medium is one of the quickest ways to see which of your marketing channels - like SEO, paid ads, or email marketing - are performing best.
You can find this data in GA4 by navigating to Reports > Acquisition > Traffic acquisition. The default report shows "Session default channel group," but you can click the dropdown arrow on that primary dimension and select Session medium to see the specific data we're talking about today.
A Complete Guide to Default Mediums in Google Analytics
Google Analytics automatically identifies several common mediums. While you can create your custom ones, these are the ones you'll see populating your reports most frequently.
1. Organic
This medium represents traffic from users who found your site through a non-paid search engine result. When someone types a query into Google, Bing, or DuckDuckGo and clicks on a regular, unpaid link that leads to your site, GA4 categorizes that visit as "organic."
What it means: Your search engine optimization (SEO) efforts are working. People are finding you through searches related to your content or brand.
Example: A user searches "how to make a sourdough starter," clicks on your blog post in the search results, and lands on your website.
2. CPC (or PPC)
Short for "Cost-Per-Click" (or "Pay-Per-Click"), this medium tracks traffic from your paid advertising campaigns on platforms such as Google Ads or Bing Ads. Google Analytics recognizes this medium when you have its ad platform, Google Ads, auto-tagging enabled in your account settings, or if you manually tag your paid ad URLs through UTM parameters.
What it means: Someone clicked on one of your paid advertisement links. It’s the clearest direct measurement of your paid search return on ad spend (ROAS).
Example: You are running a Google Ad for "vegan leather shoes." When a user searches for that term and clicks your ad that appears at the top of the search results page, their visit is registered as using the “cpc" medium.
3. Referral
This traffic comes from users who arrive at your site by clicking on a link from another domain. When someone clicks that link and comes to your website, that visit is tracked as a “referral.”
What it means: Other sites are sending traffic your way. This could be due to content partnerships, press mentions, or simply because another creator found your content valuable enough to link to.
Example: A popular food blog includes a link to your blog in their roundup of favorite cooking websites. Every person who clicks on the link to land on your website would appear as a "referral" visit.
4. Email
This medium tracks traffic coming directly from links within an email. For Google to know that traffic came from an email, you must append special URL tags to your links using UTM parameters, specifically utm_medium=email. Without them, this traffic will likely be miscategorized as "direct" or as some "referral" because GA lacks the context otherwise.
What it means: Your email marketing campaigns are successfully driving engagement and prompting recipients to visit your site for more details.
Example: You send out a newsletter featuring a promotion on your new hoodies with a hyperlink for more products. Anyone who clicks on that link to go to your site will be categorized under the “email” visit.
5. (None)
This medium typically refers to traffic that GA cannot attribute to a particular source, resulting in a "direct" channel group. It refers to when visitors enter your site's URL directly into their browser or arrive by clicking on a bookmark. It could also include cases when tracking code is missing from internal marketing links (e.g., untagged PDFs or apps) or missed due to browser security that blocks referrer data.
What it means: People know your brand URL. They might type it from word-of-mouth, marketing, or return visits by bookmarking your site. A high rate of direct traffic often indicates strong brand equity.
Example: Someone hears about your cool e-commerce site from a friend and, when they get home, types yourwebsite.com directly into their browser.
6. Social
Google tries its best to automatically detect traffic from social network websites. Visits from platforms such as Reddit, Facebook, or Instagram are often categorized under the "social" medium. For better tracking and accuracy, it is recommended to always tag those social URLs using UTM parameters with utm_medium=social.
What it means: Your content and engagement in social networks are performing successfully. They draw new interest in your business.
Example: An Instagram Story includes a link leading directly to your new blog post. Every person clicking the Swipe Up CTA would appear as having a “social” traffic medium.
7. (Not Set)
This is often confused with the "(None)" medium but is different. "(Not set)" generally indicates that GA didn't receive information on a particular session. This may be due to a malformed setup using one of the UTM tags or if your campaign lacks all necessary parameters. It could also result from technical issues like poorly set-up landing pages where tracking code wasn’t installed correctly.
What it means: There are gaps in your tracking data. This often means a marketing campaign is misconfigured, possibly missing a
utm_mediumcode, or technical issues have prevented tracking.Example: Your marketing team sends out a link but forgets to include the
utm_medium. When people click the link, Google Analytics won't know the medium, causing it to appear as “(not set)”.
Why Consistent Medium Tracking is So Important
Tracking your mediums lets you stop guessing and start making data-driven decisions. By ensuring your traffic is neatly bucketed, you can clearly identify:
Which channels drive conversions: Are your SEO efforts (
organic) leading to more sales than your paid ads (cpc)? Accurately analyzing data on channel performance helps optimize your marketing spending to improve ROIs.The value of backlinks: By monitoring ‘referral’ traffic data trends from specific websites, you can identify high-quality links and gain insights into SEO benefits for partnership opportunities.
Email Marketing Effectiveness: Having a correct setup helps determine email engagement and relates to ROI, assisting in improving targeted marketing efforts.
Take Control of Your Mediums with UTM Parameters
The key to clean and accurate, consistent data in reports is setting and using UTM parameters correctly to track performance. UTM is a simple text snippet appended to your URL telling GA specific details about the traffic, including the source, medium, and campaign. This is crucial if you use third-party sources like newsletters, email platforms, referral networks, or social media websites to send you traffic.
To keep your mediums sorted correctly, focus on including the following tags in your URLs for any campaign:
utm_source: Where the website visitors are coming from. (Example:
facebook,spring-newsletter)utm_medium: How users found their way to your website. (Example:
social,email,cpc)utm_campaign: Identifies the promotional efforts related to the link in question. (Example:
black-friday-sale,20-off_promo)
For example, if you want to run a newsletter about a "summer special" promotion, you would use UTM parameters to tag your email URL for better tracking:
When someone clicks through this link to your website, their session will be categorized under "email" with all related campaign attributes for performance tracking.
Best Practices for UTM Mediums: Consistency is Key
Once you choose a naming convention for your mediums, stick with it consistently across all campaigns. Using a standard naming system will ensure the quality of your data in Google Analytics. Stick with lowercase letters for simplicity and use hyphens ("-") to separate words instead of spaces for clarity.
Final Thoughts
Mastering Google Analytics mediums is like learning the secret language of your website traffic. It moves you beyond just knowing how many people visited and helps you understand how and why, illuminating which marketing channels truly drive results. Once you start tracking them accurately, you get the feedback needed to optimize your campaigns, justify your budget, and grow your business more intelligently.
Digging through GA reports and connecting that data with your ad spend from Facebook or sales from Shopify can quickly become a full-time job. We created Graphed to automate that process. We connect directly to all your key platforms - Google Analytics, ad accounts, CRM, and e-commerce stores - to give you a unified view of your performance in seconds. You can ask simple questions in plain English, like "Show me my top traffic mediums by conversion rate for last month," and get an interactive, real-time dashboard instantly. No more manual CSV exports or spreadsheet gymnastics, just clear answers.