| utm_source | claude |
| utm_medium | ai-assistant |
| utm_campaign | (set per campaign) |
| utm_id | (set per campaign) |
| utm_term | (set per campaign) |
| utm_content | (set per campaign) |
Claude is Anthropic’s assistant, used mainly at claude.ai (and in apps built on Anthropic’s API, though those don’t refer web traffic the way the chat surface does). When Claude browses the web or answers from sources, it can cite them with outbound links — and those outbound links are the only place tracking enters the picture. Claude is somewhere people read answers, not a console where you build campaigns.
That’s the key difference from every “sender” you tag in an ad account. Meta Ads, Google Ads, and the rest hand you a field for a UTM template and a click ID they append automatically. Claude hands you neither: no URL-parameters field, no gclid/fbclid equivalent, no macro substitution. So the honest framing is this — you can’t tag traffic inside Claude. You tag the links you control — your own pages, the canonical URLs you publish — that Claude may surface in an answer. Everything below follows from that.
How Claude traffic appears in analytics
When Claude links out and the browser preserves the referrer, the click usually arrives as claude.ai. But as with all AI assistants, a large share of Claude clicks carry no usable referrer at all — they land as (direct)/(none) in GA4, or merge into a generic referral bucket.
This is the dark-traffic problem in miniature. Client-side analytics reads the referrer to assign a source; when the referrer is stripped, the source disappears, and the click silently folds into your direct or unassigned traffic. You can’t change Claude’s referrer behavior. What you can do is make the link itself carry the source, so attribution doesn’t hinge on a header that may never arrive.
The UTM convention to apply
Tag the links you publish that Claude is likely to cite — documentation, comparison pages, anything written to be AI-readable — with a deliberate, consistent pair:
| Parameter | Value | Why |
|---|---|---|
utm_source | claude | Names the assistant people actually used. Keep anthropic for the company brand if you ever need it. |
utm_medium | ai-assistant | The value GA4’s native AI Assistants channel recognizes, and the shared medium across every assistant in this catalog. Lets you group Claude, ChatGPT, Perplexity, Gemini, and Copilot in one channel. |
utm_campaign | (your call) | Optional. Use it for the content theme or initiative the link belongs to. |
Values are lowercase and hyphen-separated, always. Claude, claude, and CLAUDE create three separate rows in GA4 and split your reporting for no reason.
Limitations and gotchas
- No click ID, no per-conversation token. Claude exposes nothing like
gclid. You can confirm that a click came from Claude, never which conversation or prompt produced it. - You can only tag links you control. If Claude writes a bare citation to your homepage, that link carries whatever you put on your canonical URL — and nothing if you put nothing. You can’t reach into the model’s output and append a UTM.
- Don’t UTM-tag internal links. A UTM on a link between your own pages overwrites the original source on the next pageview. Tag external-facing canonical URLs only.
- API traffic isn’t web referral traffic. Apps built on the Claude API don’t send
claude.aireferrals; this page is about the chat surface where people click citations.
Verification
- Visit your tagged URL in a normal browser and confirm the UTMs land in the address bar and register in GA4 real-time as
claude/ai-assistant. - Ask Claude a question it should answer with your page, click the citation, and inspect the landing URL and the referrer your analytics records — that shows how Claude’s referrer behaves for your domain specifically.
- Check the AI Assistants channel. Confirm your
utm_medium=ai-assistanttraffic is landing in GA4’s native AI Assistants channel instead of Unassigned. For the receiver-side mechanics, see Google Analytics .
For the bigger picture — building a convention across all five assistants and getting the most out of GA4’s native AI Assistants channel — see the related guides below.
