Track ChatGPT Referrals & Leads with Cookieless Analytics

Your customers are asking ChatGPT "best espresso machine under $200" and getting recommendations that send them to your e-commerce store. But traditional UTM analytics miss this valuable traffic due to CMP (Cookie Consent Banner) blocking, Safari's privacy settings, ad blockers, and more.

Here is how you can identify which leads and sales came from ChatGPT, using Hardal's cookieless analytics.

What Does utm_source=chatgpt.com Mean?

utm_source=chatgpt.com is the UTM tag ChatGPT automatically appends to outbound links it shows users. When someone clicks a link ChatGPT recommends, their browser lands on your site with ?utm_source=chatgpt.com in the URL and chatgpt.com set as the HTTP referrer. It's OpenAI's way of marking traffic it sent you, the same way Google marks organic clicks or Facebook marks referral clicks from its apps.

In Google Analytics 4's default channel grouping, this traffic usually shows up as chatgpt.com / referral, not as its own "AI" channel, unless you build a custom channel group for it.

ChatGPT Automatically Adds UTM Parameters

When ChatGPT references your website, it automatically adds a UTM tag to your URLs:

Your URL: https://yoursite.com/product
ChatGPT URL (current): https://yoursite.com/product?utm_source=chatgpt.com
ChatGPT URL (older sessions): https://yoursite.com/product?utm_source=chatgpt

The referrer domain is chatgpt.com (previously chat.openai.com on older sessions).

Traditional UTM based analytics often miss this traffic anyway, because cookie blocking and privacy settings like Safari's Intelligent Tracking Prevention (ITP) or Firefox's Enhanced Tracking Protection strip it before it reaches your reports.

How Hardal Captures ChatGPT Referrals

Hardal reads UTM parameters and events through its own custom tracking domain, as first-party requests. The data reaches your analytics as-is, including your website's own event data, instead of getting stripped by a browser or a cookie consent banner along the way.

{
  "type": "event",
  "payload": {
    "website": "your-website-id",
    "url": "https://yoursite.com/product?utm_source=chatgpt.com",
    "referrer": "https://chatgpt.com/",
    "utm_source": "chatgpt.com",
    "utm_medium": "referral",
    "title": "Your Product Page",
    "hostname": "yoursite.com",
    "device_type": "desktop",
    "browser_name": "Chrome",
    "created_at": "2024-01-15T10:30:00Z"
  },
  "event_name": "page_view"
}

You Get Raw First-Party Data, Not Modeled Attribution

• Automatic UTM capture - No setup required
• Cookieless tracking - Works with all privacy settings
• Complete attribution - Track from ChatGPT to conversion
• Real-time data - See ChatGPT traffic immediately

Simple API to get data

In your Hardal Analytics API, you'll see:

• Traffic Source: ChatGPT (from utm_source=chatgpt.com)
• Landing Pages: Which pages ChatGPT users visit most
• Conversions: How many ChatGPT visitors become customers
• Revenue: Direct revenue attribution from ChatGPT referrals

and your custom events and parameters.

Session Merging Success

Here's an example of how our API returns joined ChatGPT referral sessions:

{
  "data": [
    {
      "id": "a7b3f2e8d9c5a1b4e6f8g2h3i5j7k9l1",
      "referral": "chatgpt"
    },
    {
      "id": "b8c4g3f9e0d6b2c5f7h9i3j6k8l0m2n4",
      "referral": "chatgpt"
    },
    {
      "id": "c9d5h4g0f1e7c3d6g8i0j4k7l9m1n3o5",
      "referral": "chatgpt"
    },
    {
      "id": "d0e6i5h1g2f8d4e7h9j1k5l8m0n4p6q8",
      "referral": "chatgpt"
    }
  ]
}

This session merging gives you accurate visitor counts and complete user journeys, all without cookies.

See the AI Crawlers Behind the Referrals

Referral tracking shows what happens after ChatGPT sends someone to your site. It doesn't show whether ChatGPT can read your site in the first place, which is what determines whether it ever recommends you at all.

Two Hardal tools cover that side:

• isvisible.ai: a free, instant check of whether ChatGPT, Claude, Perplexity, and Google AI can access your site. Enter your URL and get an agent-by-agent access map across 13 AI crawlers, including OAI-SearchBot, the crawler that indexes pages for ChatGPT search citations.
• Hardal AI Visibility (beta): tracks those crawler visits continuously instead of a one-time snapshot. It identifies crawlers like GPTBot, ClaudeBot, and OAI-SearchBot by name, attributes each to its parent platform, and shows exactly which pages they read and which ones they're missing, on the same first-party, server-side pipeline as Hardal Analytics.

AI Visibility is in beta. Join the waitlist for early access.

Referral tracking and AI Visibility cover different ends of the same funnel: whether AI crawlers can find your pages, whether that turns into a citation, and whether the citation turns into a click and a conversion.

Frequently Asked Questions

How do I know which leads found me from ChatGPT?

Every lead form submission, signup, or purchase Hardal records keeps its original utm_source=chatgpt.com and referrer data attached to that visitor's session. Filter your leads or conversions by traffic source in the Hardal dashboard to see exactly which ones started with a ChatGPT recommendation, without relying on self-reported "how did you hear about us" fields.

What is ChatGPT's referrer domain?

chatgpt.com. Older sessions can still show chat.openai.com. Hardal captures both as first-party events, so a domain change on OpenAI's side won't create a gap in your data.

How do I track ChatGPT traffic without cookies?

Hardal reads the UTM parameters and referrer straight off the incoming request on its own custom tracking domain, before any cookie consent banner, Safari ITP, or ad blocker gets a chance to strip them. No client-side cookie is required to attribute the session.

Does this work for other AI assistants, not just ChatGPT?

Yes. Perplexity, Claude, Google AI Overviews, and Copilot each send their own UTM parameters or referrer headers when they link to your site, and Hardal captures all of them the same cookieless way. If you're trying to measure traffic and leads from AI answer engines generally, not just ChatGPT, the same setup covers it.

Can I see which pages on my site ChatGPT is reading?

Yes. Hardal AI Visibility's Pages view shows which URLs each AI crawler reads most, including OAI-SearchBot (ChatGPT's search indexer) and GPTBot, and which of your important pages they're missing. For a free one-time check instead of continuous tracking, run your URL through isvisible.ai.

Why This Matters

Many e-commerce companies discover that 15-25% of their "unknown" and "not-set" traffic is actually from ChatGPT and other AI assistants. With Hardal's cookieless tracking, you can:

• See your real ChatGPT traffic (not just "direct" visits)
• Optimize content that ChatGPT frequently references
• Track revenue and leads from AI-driven referrals
• Understand user behavior from ChatGPT and other AI assistant visitors
• See the full funnel, from AI Visibility's crawler data through to the referral clicks and conversions on this page