What are UTM parameters?
UTM parameters decide which campaign gets credit for a lead. Tag them well and your CRM can tie pipeline back to the email, ad or post that started it.
How UTM parameters work
A UTM tag is a key and a value added after a question mark in a link. When someone clicks the link, your analytics tag reads the values and stores them with the session. Your page loads the same as always; only the reporting changes.
Say you post a link to a new RFQ guide in a LinkedIn ad. Tagged, it looks like this:
Example: yoursite.com/rfq-guide/?utm_source=linkedin&utm_medium=paid-social&utm_campaign=rfq-guide-q4&utm_content=video-a
In Google Analytics 4, that visit shows up with session source “linkedin”, medium “paid-social” and campaign “rfq-guide-q4”. If the visitor fills out a form, the same values can travel into your CRM with the lead.
What each tag records
utm_source
The site or platform that sent the click: google, linkedin, newsletter, a partner’s domain. Required.
utm_medium
The type of traffic: cpc, paid-social, email, referral. GA4 uses it to sort visits into channels, so stick to standard values. Required.
utm_campaign
The specific push: a launch, a quarter’s RFQ offer, a webinar. Required for anything you plan to report on.
utm_term
The paid keyword or audience. Google Ads fills this automatically with auto-tagging, so it matters most for Microsoft Ads and social audiences.
utm_content
Which creative, link or button got the click. Use it to compare two ads or two links in the same email.
Extra GA4 tags
GA4 also reads utm_id, utm_source_platform, utm_creative_format and utm_marketing_tactic. Use them once the core five are clean.
Naming conventions and common mistakes
UTM values are case-sensitive in GA4. “LinkedIn”, “linkedin” and “linked_in” become three sources. A short naming sheet that everyone uses fixes most of the mess.
- Use lowercase everywhere and hyphens between words.
- Pick a fixed list of mediums that match GA4’s default channel rules: cpc, paid-social, email, referral, display.
- Name campaigns so they sort: offer, audience and quarter, such as rfq-guide-q4.
- Never tag internal links. A UTM on a link inside your own site starts a new session and overwrites the real source of the visit.
- Test links after redirects. Some redirects and link shorteners drop the query string.
- Leave Google Ads to auto-tagging. Manual tags on top of the gclid can conflict.
Capturing UTMs in GA4 and your CRM
GA4 stores the tags as session source, medium and campaign, and as first user source for a visitor’s first visit. Mark your form submission as a key event and you can see which campaigns produce leads.
Your CRM needs the values too. Add hidden fields to each form, fill them from the URL or a first-party cookie set on landing, and map them to contact properties. HubSpot records its own original source, and the UTM fields add campaign-level detail. That is what lets closed-loop reporting tie a closed deal to the campaign that started it. We set this up as part of our CRM and tech integrations work.
Where AI referral traffic lands
AI assistants decide how the links in their answers are tagged. Most clicks from ChatGPT, Perplexity, Gemini and Copilot arrive with no UTM tags at all. Some assistants add a utm_source of their own to some links, and that shows up in GA4 as written.
The rest splits two ways. When the browser passes a referrer, GA4 files the visit as Referral with a source like chatgpt.com or perplexity.ai. When the referrer is missing, as it often is from desktop and mobile apps or copied links, the visit lands in Direct. To see the first group clearly, build a custom channel group in GA4 for AI referral traffic using a regex on known assistant domains. The second group only shows up as unexplained growth in direct visits. Search Console fills in part of the picture, and our guide to finding AI conversations in Search Console shows how.
From our work
That pattern shows up in our client data. For an industrial ground monitoring manufacturer, direct sessions rose 242.1% alongside 4,500 AI citations across just 18 pages in six months. For a 3PL fulfillment provider, direct users rose 195% quarter over quarter, the dark AI funnel, while organic search sessions rose 21%. Neither lift carries a single UTM tag. We cover how to read it in our guide to the dark funnel from AI search and in solving AI search attribution.
UTM setup checklist
- Write a one-page naming sheet: sources, mediums and the campaign pattern.
- Build links from a shared template so nobody types tags by hand.
- Click every tagged link once and confirm it in GA4 Realtime.
- Add hidden UTM fields to every form and map them in the CRM.
- Create a GA4 channel group for AI assistants.
- Add a “How did you hear about us?” field for the visits UTMs can never see.
Related terms
- Self-reported attribution: asking buyers where they heard about you.
- Multi-touch attribution: spreading credit across every tagged touch.
- Dark social: shares in private channels that arrive untagged.
- First-touch attribution: crediting the first source a buyer came from.
Frequently asked questions
Do UTM parameters affect SEO?
No, as long as your pages carry a canonical tag pointing to the clean URL. Keep UTMs off internal links and out of your sitemap so search engines see one version of each page.
Which UTM parameters are required?
Source and medium are the minimum GA4 needs to assign a channel. Add campaign to anything you plan to report on. Term and content are optional.
Are UTM parameters case-sensitive?
Yes. GA4 treats “Email” and “email” as different values, which splits your reports. Use lowercase for every tag.
How do I track traffic from ChatGPT in GA4?
Look in Referral traffic for sources like chatgpt.com, then build a custom channel group that matches AI assistant domains. Expect part of that traffic to sit in Direct with no referrer.
Know which clicks become pipeline
We connect tagging, GA4 and your CRM so paid, organic and AI search traffic can each be traced to the leads and revenue they produce.
