How to track ChatGPT and Perplexity traffic in GA4

GA4 sorts every session into a channel using its default channel group. Google's channel definitions now include an AI Assistant channel, described as visits "from sources like ChatGPT, Gemini, Deepseek, Copilot, or Grok."

Google's own AI features are counted differently. The same page defines Organic Search as including visits from links in Google's AI Overviews and AI Mode, and it says the AI Assistant channel excludes them. So if you want to know what Google's AI features send you, look inside Organic Search. The AI Assistant channel covers the other assistants.

OpenAI's publisher FAQ says ChatGPT automatically adds utm_source=chatgpt.com to referral URLs from ChatGPT search results, so publishers can track that traffic in tools such as Google Analytics. In GA4, look for chatgpt.com as the session source. That is the simplest way to find ChatGPT traffic in GA4.

There is one condition. ChatGPT has to be able to reach your pages in the first place. The same FAQ says that for your content to appear in ChatGPT's summaries and snippets, you should not block OAI-SearchBot. OpenAI's crawler documentation explains that OAI-SearchBot and GPTBot are separate settings. You can allow OAI-SearchBot so your site can appear in search results while disallowing GPTBot, which OpenAI uses to signal whether content may be used for training.

Perplexity lists two agents on its crawlers page. PerplexityBot surfaces and links websites in Perplexity's search results, and Perplexity says it is not used to crawl content for AI foundation models. Perplexity-User visits a page when someone asks Perplexity a question, so it can cite that page in the answer.

Those are machine visits. What you measure in GA4 is the person who clicks a link in the answer and lands on your site. Perplexity is not one of the examples in the default AI Assistant description, which is why it is worth building your own channel and checking that it catches Perplexity visits.

Google's help page on custom channel groups walks through this exact case. Its example creates a channel named "AI assistants," adds a condition that "matches regex," and lists popular assistants such as ChatGPT, Gemini, Microsoft Copilot, Claude and Perplexity.

1. Create a new custom channel group, or edit one you already use.
2. Add a channel named AI assistants.
3. Add a condition set to "matches regex" and paste in a pattern for the assistant domains. Google's help page includes a sample pattern you can start from.
4. Move AI assistants above Referral in the channel list. Google's instructions say to reorder it that way so the data is processed correctly.
5. Open the User acquisition or Traffic acquisition report and choose your new channel group as the primary dimension, as Google's steps describe.

Google also notes that custom channel groups can be applied to your reports retroactively, so you can look back at past data once the channel exists.

Volume alone tells you very little. Three views make the AI assistants channel useful.

Landing pages. Look at which pages AI visitors land on. Each of those visits started with a link to that page, so the list shows which of your pages the assistants point people to. If it is all blog posts and no service pages, you know where to add a clear next step.

Key events. GA4 lets you choose which actions count as key events. Google's list of recommended events includes generate_lead, for when someone submits a form or a request for information. Mark the actions that matter to your business as key events, then compare how often AI assistant sessions complete them with how often Organic Search sessions do.

The trend. Check the channel monthly rather than daily. Small numbers swing a lot, and a handful of visits from one shared answer can look like a spike.

Some AI influence will never show up as an attributed visit, and it helps to plan for that.

Answers without clicks. When someone reads an assistant's answer and never clicks, there is no visit for GA4 to record. Your name may still have reached them.

Copied links and some apps. If someone copies your web address into a new tab, or an app opens your link without passing along where it came from, GA4 has very little to go on. Google defines Direct as visits that arrive "via a saved link or by entering your URL," and that is where those sessions usually end up.

Searches that happen later. A person who hears your company name in ChatGPT and searches for it on Google tomorrow shows up as Organic Search or Direct, not as AI.

1. Ask people. Add a How did you hear about us? question to your forms and phone intake, and include ChatGPT and other AI tools as answer choices.
2. Watch brand searches. Track searches for your company name in Search Console next to your AI assistant sessions. If both rise together, the assistants are probably part of the story.
3. Check what the assistants say. Our guide to tracking your brand in AI search covers how to see what ChatGPT and others say about you, and how to rank in ChatGPT covers what helps you get mentioned in the first place.

AI assistant traffic is measurable today, and setting up the channel now gives you history to compare against as it grows or shrinks.