Every visit is sorted into exactly one channel. This page gives the rules, in the order they are applied, so you can always work out why a particular visit landed where it did.
The Traffic sources card with the Channels tab selected, showing a realistic distribution across Direct, Organic Search, Referral, Social, AI and Campaign. Light theme.
The rules, in order
The first rule that matches wins. Nothing below it is considered.
| # | Channel | Matches when |
| 1 | Paid Search | utm_medium is cpc, ppc, paid or paidsearch |
| 2 | utm_medium is email or newsletter | |
| 3 | AI | the referrer's host is ChatGPT, OpenAI, Perplexity, Claude, Gemini, Copilot or Phind |
| 4 | Organic Search | the referrer's host is Google, Bing, DuckDuckGo, Yahoo, Yandex, Baidu, Ecosia, Brave, Qwant, Ask or Startpage |
| 5 | Social | the referrer's host is YouTube, Twitter/X, Facebook, LinkedIn, Reddit, Instagram, TikTok, Pinterest, Mastodon, Threads, t.co, t.me, fb.com or lnkd.in |
| 6 | Campaign | any utm_source or utm_medium is present that did not match rules 1–2 |
| 7 | Direct | there is no referrer, or the referrer is one of your own hostnames |
| 8 | Referral | anything else |
Matching is on the referrer's hostname, and it covers subdomains: news.
google.com matches Google.
The AI channel
Rule 3 is the one other analytics tools do not have. A visit from a link inside a ChatGPT answer, a Perplexity citation or a Claude conversation lands in AI rather than being swept into Referral.
This is a different measurement from the AI crawler panel, and it is worth keeping the two apart:
The AI channel counts people who arrived from an AI product. A human clicked a link in an answer.
AI visibility counts crawlers that fetched your pages. No human involved.
One is demand and one is supply. Together they answer "are the assistants reading me, and is that turning into visits" — which is the question neither number answers alone.
Note that many AI products strip the referrer, so the AI channel undercounts for the same reason every referrer-based measurement does.
Why order matters
Rule order explains most surprises.
A UTM-tagged link from Twitter shows as Campaign, not Social. If the link
carried utm_source=twitter&utm_medium=social, rule 6 has already claimed it
before rule 5 is reached — because a UTM tag is an explicit statement about how
you classified the link yourself, and honouring it is the point of tagging.
A cpc-tagged link from anywhere is Paid Search. Rule 1 is first and does
not look at the referrer at all.
A link from your own site is Direct, not Referral — but only if you have listed that hostname under Self hosts.
Self hosts: list your own hostnames
If you do not, internal navigation shows up as referral traffic from yourself, and your Referrals card is topped by your own domain.
Site settings → Self hosts. Add every hostname you own that links into this
site: example.com, www.example.com, blog.example.com.
This matters most on multi-subdomain setups, where a click from the marketing site to the docs would otherwise be counted as an outside referral into the docs.
Direct is not always direct
Direct means "we have no referrer", which covers more than someone typing your URL:
A link opened from a desktop email client, a PDF or a chat app
A link from an HTTPS page to an HTTP one (the browser withholds the referrer)
A site whose referrer policy suppresses it — which many now do
A browser or extension stripping it
This is why Direct is usually the largest channel on any site, everywhere. It is not a measurement error; it is the limit of what a referrer can tell you.
The way to shrink it is to tag your own outbound links with UTM parameters, which moves them into Campaign where you can see them.
Filtering by channel
Click a channel row and the whole dashboard filters to it. Combine it with Top pages to answer "what do people from search actually read", which is a different question from either card alone.