AI referral traffic

AI referral traffic is the visits that reach your website from links in AI assistants' answers, such as ChatGPT, Gemini, Claude, Microsoft Copilot and Perplexity. It comes from clicks on the citations and links in an answer.

How GA4 counts it

Google Analytics 4 added AI assistant traffic measurement in 2026. When a visit's referrer matches Google's list of AI assistants, GA4 sets the medium to ai-assistant and the campaign to (ai-assistant), and the default channel group places the visit in the AI Assistant channel. Google gives ChatGPT, Gemini and Claude as examples, so check where visits from other assistants, such as perplexity.ai, land in your property.

Where it goes missing

• No referrer. A visit with no referrer and no campaign tags, such as a link copied into a browser, is recorded as Direct.
• Google's own AI features. Clicks from AI Overviews and AI Mode come from Google Search, so GA4 sorts them into Organic Search with other Google visits. Google includes them in Search Console's overall search traffic, in the Performance report under the Web search type.
• No click. A buyer who reads an answer and later searches for your brand arrives as branded search, not as AI referral traffic.

How to use it

Compare sessions, key events and landing pages for AI referrals with your other channels, and line the trend up with your AI visibility. Referral traffic shows the visits that answers send. Visibility shows how often answers name you, including all the times nobody clicks. For example, a month in which visibility rises and AI referrals stay flat suggests buyers are reading about you without clicking, so watch branded search for the follow-through.