Methodology: sources, dates and evidence labels
How facts get onto this site, what the labels mean and what we have not done yet.
Last checked · How we check
On this page
How a fact gets onto this site
- We find a primary source: a vendor's documentation, a release note, a published test or a study.
- We read it, not a summary of it where we can avoid that, and record the date we read it.
- We publish the statement with a link and the date. Where we only have a secondary source, the page says so.
- Where two sources disagree, we show both and do not pick one.
- Where we found nothing, we write "not stated" or "unknown" and leave a hostname out of strict filters.
Evidence labels
| Label | Meaning |
|---|---|
| Vendor documentation | A page of the analytics or AI vendor states it |
| Third-party test | Someone tested it and published method and result; we cite the date of the test |
| Own test | We tested it and kept the data (none yet) |
| Observed in logs | Seen in our own counts (none yet) |
| Unverified | Appears in third-party lists; no source or test we could read |
Limits
- We have not re-tested any assistant ourselves. Most behaviour rows rest on a test from May 2025.
- We have not checked GA4's channel list in a live property, so the two sources we compare stay unresolved.
- Some sources could not be read (an OpenAI help page returned HTTP 403). We do not claim what they say.
- Tool syntax that the vendor's page does not show is labelled unverified in the generator.
Sources and when they were read
| Source | What it covers | Status |
|---|---|---|
| Google Analytics Help: release notes (13 May 2026, AI Assistant traffic measurement) | GA4 channel, medium ai-assistant, campaign (ai-assistant); names ChatGPT, Gemini and Claude. | Read, original |
| Search Engine Journal: GA4's AI Assistant channel undercounts your AI traffic | Account of GA4's later documentation and rollout. Conflicts with the release note on which assistants are named. | Read, secondary |
| Google Analytics Help: About regular expressions | Full match by default and case-sensitive. | Read, original |
| Google Analytics Help: Custom channel groups | Matches regex conditions; first matching channel wins. | Read, original |
| Plausible: track AI traffic | AI Assistants channel; assistants named; referrer or UTM required; known AI crawlers filtered. | Read, original |
| Plausible docs: filters and segments | Operators is, is not, contains, does not contain. | Read, original |
| Matomo FAQ: track and analyse traffic from AI assistants | AI Assistant channel type, eight assistants, version 5.5.0, segment, retroactivity. | Read, original |
| PostHog docs: web analytics dashboard | Channel type AI; session attribution explorer. | Read, original |
| Adobe Experience League: marketing channel rules | Condition "Referrer Is Conversational AI"; rules run top to bottom. | Read, original |
| Cloudflare docs: Web Analytics dimensions | Referer dimension; no AI grouping documented. | Read, original |
| Ahrefs: generative engines are breaking web analytics | Referrer test per assistant and surface (May 2025); utm_source=chatgpt.com on source links. | Read, original |
| Patrick Stox: AI traffic attribution | Table form of the surface results, including Grok, Copilot and DeepSeek. | Read, secondary |
| PPC Land: ChatGPT adds UTM parameters to more links | Reports from 13 June 2025; links under "More". | Read, secondary |
| OpenAI bots documentation | OAI-SearchBot, GPTBot, ChatGPT-User. Mentions no referrer or UTM behaviour. | Read, original |
| Perplexity bots documentation | PerplexityBot, Perplexity-User. Mentions no referrer or UTM behaviour. | Read, original |
| Google Search Central: AI features and your website | AI features traffic is counted under Web in Search Console; says nothing about referrers. | Read, original |
| OpenAI help article on ChatGPT links and UTM | The article we looked for returned HTTP 403 to our reader. We have not read it and make no claim about what it says. | Not read |
All sources were read or attempted on 2026-10-19.
Privacy of the tools
The generator, the checker and the cleaner run in your browser. What you type is not sent to us and not stored. The site itself counts page views without cookies and counts requests from known AI and search bots; the privacy notice says exactly what.