AI referrer domains
The hostnames AI assistants send traffic from, and — the column that actually matters — whether each one tells your analytics where the visit came from.
Use these hosts to build a channel group in Google Analytics, or to filter your server logs. Escape the dots if you are writing a regular expression, and order the AI channel above Referral, because GA4 stops at the first match.
Dataset version 2026-08-06, updated 2026-08-06. 11 records.
| Referrer host | Assistant | Strips referrer | Added | Notes |
|---|---|---|---|---|
chatgpt.com | ChatGPT | No | 2026-08-06 | Also appends utm_source=chatgpt.com on outbound links, which survives referrer stripping. |
chat.openai.com | ChatGPT | No | 2026-08-06 | Legacy host, still seen in historical analytics exports. |
perplexity.ai | Perplexity | No | 2026-08-06 | — |
gemini.google.com | Gemini | No | 2026-08-06 | — |
bard.google.com | Gemini | No | 2026-08-06 | Pre-rename host; appears in historical exports. |
claude.ai | Claude | Yes — arrives as direct | 2026-08-06 | Outbound links are sent with rel="noreferrer", so most real visits appear as Direct. |
copilot.microsoft.com | Microsoft Copilot | No | 2026-08-06 | — |
bing.com | Microsoft Copilot | No | 2026-08-06 | Copilot answers served inside Bing refer as bing.com; indistinguishable from ordinary Bing search without a UTM tag. Rows from this host are reported as estimated. |
grok.com | Grok | No | 2026-08-06 | — |
chat.deepseek.com | DeepSeek | No | 2026-08-06 | — |
meta.ai | Meta AI | Yes — arrives as direct | 2026-08-06 | — |
What the strips-referrer column means
2 of the 11 hosts here send outbound links with the referring page removed. When that happens the visit is real and the reader is real, and your analytics files it as direct traffic because nothing identifying the source was ever transmitted.
This is not a configuration problem and no tool recovers it afterwards. It means any AI referral figure — ours included — is a floor rather than a total, and it means the assistants most protective of their users are the ones your reports will show as sending nobody. See referrer stripping for what can still be measured.
Changelog
- 2026-08-06 — Initial registry: eleven referrer hosts across seven assistants.