Awesome GEO

Track ChatGPT and Perplexity traffic in GA4 with a regex

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Awesome GEO’s AI traffic filter builds a regular expression that matches visits referred by ChatGPT, Perplexity and other AI assistants. Paste it into a GA4 exploration or a custom channel group and you have one report of those visits. Both routes are below, with the menu names.

Before you start

You need a GA4 property that is already collecting data and a web browser. The filter is free, runs in your browser and makes no server calls. This page describes it as read on 11 November 2026, and its hostnames come from the referrer lists maintained by Matomo, Adobe Analytics, PostHog and Plausible, checked in November 2026.

This page is written by the maker of Awesome GEO, which is built and maintained by Dmitry (Dee) Kargaev, a design engineer and independent GEO researcher in Los Angeles.

Build the regex in the AI traffic filter

  1. Open the AI traffic filter in your browser.
  2. Look under “Assistants”. Ten are checked to start: ChatGPT, Perplexity, Gemini, Copilot, Claude, DeepSeek, Grok, Meta AI, Le Chat and Duck.ai. Keep ChatGPT and Perplexity checked, and uncheck any others you do not want in the report.
  3. Use the “More” toggle if you need an assistant that is not listed. It shows 15 further assistants, unchecked by default.
  4. Click “GA4 regex” under “Filter”. The tool shows one regular expression labelled “Session source matches regex”.
  5. Press “Copy” on that output.

Use the regex in a GA4 exploration

The GA4 steps below follow rankshift.ai’s guide to tracking Perplexity referrals, which sets out both an exploration and a custom channel group. An exploration gives you a saved view that you can slice by page, device or location, and compare engagement across sources.

  1. In GA4, open Explore and create a custom exploration.
  2. Add the metrics Sessions, Engaged sessions, Average session duration and Conversions.
  3. Click “Filter”, choose Session source/medium (the guide names Page referrer as the other choice) and apply the regex you copied. The report now shows only AI sources.
  4. Save the exploration and name it, for example “AI Traffic”.

Use the regex in a custom channel group

A custom channel group makes AI traffic its own channel in GA4’s acquisition reports. rankshift.ai gives the path as Admin, then Data settings, then Channel groups, then Custom channel groups. onemetrik.com gives Admin, then Data display, then Channel groups, so try that path if you do not see the first.

  1. Go to Admin, then Data settings, then Channel groups, then Custom channel groups.
  2. Click “Create new channel group” and base it on the default channel grouping.
  3. Add a rule called “AI Traffic”. Set Medium equals referral, and set Source to match the regex you copied.
  4. Move the AI Traffic rule above Referral and save. GA4 assigns each session to the first channel it matches, top to bottom, so the order decides whether AI visits land in your rule or in Referral.
  5. Open Reports, then Acquisition, then Traffic acquisition, and select your new channel group. AI Traffic now shows as its own channel.

Check the numbers

The designcopy.net guide suggests comparing your AI channel with the raw rows it should contain. In Reports, then Acquisition, then Traffic acquisition, look at Session source and add up the rows for chatgpt.com and perplexity.ai. The guide says the total should line up closely with the channel, and that if it does not, the regex is probably missing a host or the rule sits below Referral.

authoritytech.io adds a second check: select Session source / medium, find perplexity.ai and read its actual medium rather than assuming it is referral or ai-assistant.

Read the report

Click a row to drill down. rankshift.ai suggests looking at Engaged sessions, Average engagement time, Conversions and Revenue to see whether Perplexity traffic performs differently from other referrals.

Adding another assistant later

searchlogistics.com notes that a regex does not catch a new AI tool until it is updated. To add one, check it in the filter, copy the new expression and paste it over the old one in GA4.

If you do not use GA4

“Hostnames” gives the referrer hostnames, one per line. “grep” gives a grep -E command for the referrer field of a combined access log.

What this misses

The AI traffic filter lists four limits in its “What this misses” section.

  • Google AI Overviews and AI Mode count as normal Google search clicks, and Search Console’s generative AI report shows impressions only, with no clicks.
  • Bing’s AI Performance report shows citations for Copilot and Bing summaries, with no clicks.
  • Assistant apps on phone and desktop mostly send no referrer, so those visits land in Direct, and any number from the filter should be treated as a floor.
  • GA4’s built-in AI Assistant channel covers ChatGPT, Gemini, DeepSeek, Copilot and Grok; the filter adds the rest.