UTM link building: what the parameters do and how to track placed links

UTM link building means adding a short tag to the end of the URL inside a placed link (a backlink that was ordered or pitched), so that Google Analytics reports the visit under the tag's values instead of only under the site it came from. The tag is a string of parameter and value pairs, and it travels with the click. Because the tag goes on the URL you supply, whether a placed link carries one is decided when the link is ordered or pitched, not after the page is live. A placed link with no tag still shows up in your reports, filed under the linking site's name, whenever the browser passes on the site the visit came from.

This page sets out what each parameter does in Google's own words, where the values appear in Google Analytics 4, what changes with and without a tag on a placed link, what placed links send by the counts available, and what we report on a placement. It is written for people who place links on other sites, or who order them, and who want to know which placement sent a visit. If you track link building by the visits each placement sends, the tag is what tells two links on the same site apart and groups many sites under one campaign.

What UTM parameters do

Google's Analytics Help page on URL builders explains what the tag does: "By adding utm campaign parameters to the destination URLs you use in referral links and ad campaigns, you can view which campaigns refer traffic. When a user clicks a referral link, the URL parameters are sent to Analytics, and the parameter values are visible in the Traffic acquisition report." The tag is written into the URL itself: a question mark after the page address, then the parameters as name and value pairs joined by equals signs, with an ampersand between each pair. One of the same page's example URLs ends in ?utm_source=exampleblog&utm_medium=referral&utm_campaign=summer-sale, which sets a source, a medium of referral and a campaign. Google's Campaign URL Builder builds the tagged URL from a form, so the pairs come out in the right shape, though you can also write them by hand. The values are yours to choose, and they are the values the reports group by later.

The same page is direct about which parameters to set: "When you add parameters to a URL, you should always use utm_source, utm_medium, and utm_campaign." In plain terms, utm_source names where the visit came from, utm_medium names the kind of traffic, and utm_campaign names the effort the visit belongs to. The page is just as direct about spelling: "Parameter values are case sensitive, e.g. utm_source=google is different from utm_source=Google." So one agreed spelling of each value is kept and used on every link, and the same page suggests lowercase as a standard practice.

The nine parameters Google lists

Google's URL builders help page lists nine parameters in total, and it says two of them are not currently reported. The middle column below is Google's own definition, word for word; the right column is our example for a placed link.

The same help page recommends that if you set one parameter, you set all the relevant ones, because missing parameters show up as (not set) in reports.

Does a tag belong on a placed link?

The URL inside a placed link is the one supplied by whoever ordered or pitched the link, so the tag decision is made at that moment, not after the page is live. If you write the piece and place it yourself, the choice is yours when you add the link. With us, you supply the target URL and the anchor text when you order a Guest Post or a Curated Link, so if you want a tag on a placed link, ask us before you order.

What a tag changes inside Google Analytics 4 comes down to channel rules. Google's Analytics Help page on the default channel group defines the Referral channel: "Referral is the channel by which users arrive at your site via non-ad links on other sites/apps (e.g., blogs, news sites)." For traffic tagged by hand, the same page's rule puts a visit in Referral when the medium is referral, app or link. A medium of your own, such as guest-post, matches no listed rule, and the page says: "Unassigned is the value Analytics uses when there are no other channel rules that match the event data." So a tagged placed link with a medium of referral stays in Referral and gains a campaign value, while one with a made-up medium lands in Unassigned unless a custom channel group is built for it. Both outcomes hold only when the source and campaign name match none of the page's other rules, such as its lists of search, social, video and shopping sites. Custom channel groups are set in Admin, under Data display, Channel groups, per Google's help page on custom channel groups, and the same page notes that a custom group can be applied to your reports retroactively, so a medium chosen today can still be grouped later.

One more behaviour is worth knowing before you tag. Google's Analytics Help page on campaigns and traffic sources says the values in a tag map directly to the source, medium and campaign in reports, and that the referring page can set those values only when no campaign values have been set. A tag therefore replaces, rather than adds to, what Analytics would have read from the linking page.

What to read when no tag goes on

An untagged placed link is already visible by site. In the Traffic acquisition report, under Reports and then Acquisition, the Session source dimension carries the linking site and the Session medium reads referral, so the visit is counted against the site the link sits on. Google's page on campaigns and traffic sources adds that a visit is processed as direct traffic when no information about the referral source is available; a tag travels inside the URL, so it still names the placement when that information is lost. For the page behind the visit, Google's help page on dimensions defines Page referrer: "The referring URL, which is the user's previous URL and can be your website's domain or other domains." Where the full address is passed on, the linking page itself can be read, not only its domain. For a single placement, that reading is often enough; a tag earns its keep when two links sit on the same site or when several placements belong to one campaign.

Other parties add tags of their own, and those are worth knowing about because they change where a visit is filed. Vincent Ruan of Attrifast, an analytics software company, ran 80 prompts through ChatGPT on 4 October 2026 and counted the tags on the links it cited. Attrifast's count of tagged links found that "179 of 194 cited links (92.3%) carried utm_source=chatgpt.com." The count covers one tool's citations on one day. Google's default channel group page also lists an AI Assistant channel for visits from sources such as ChatGPT, Gemini, Deepseek, Copilot or Grok. A visit tagged utm_source=chatgpt.com came from a link in a ChatGPT answer, not from a placed link.

Reading the result in Google Analytics 4

Everything above lands in one report. Google's Analytics Help page on the Traffic acquisition report describes it: "The Traffic acquisition report is a pre-made detail report that's designed to help you understand where your website and app visitors are coming from." The report sits under Reports, then Acquisition. The dimensions to switch between are Session source / medium, Session source, Session medium and Session campaign, and the column that counts the events you mark as most important is called key events. Switching the dimension is how the same visits are read by site, by medium or by campaign.

Attribution for that report is settled by the scope of the dimension. Google's page on scopes of traffic-source dimensions says: "For user-scoped and session-scoped dimensions, Analytics uses the paid and organic channels last click attribution model." So the Traffic acquisition report credits each session to one traffic source, and changing the property's attribution model does not change that.

One setting is worth a check. The data retention setting offers 2 months or 14 months on standard properties, under Admin, Data settings, Data retention, and Google's page on data retention says: "The data retention setting only affects explorations and funnel reports." The same page says the setting does not affect the standard aggregated reports, so the choice only changes how far back your explorations and funnel reports reach. Metric definitions for the rest of GA4 are in the SEO metrics guide.

What placed links send

The counts available are thin, and they come from other people's measures rather than from tagged placed links, so each is stated with its owner and its date. Ahrefs, a company that makes SEO software, reports that its chief marketing officer, Tim Soulo, asked more than 500 bloggers how much traffic their guest articles brought; the page is dated 4 August 2023 and gives no date for the survey itself. The finding, in the page's own words: "The average referral traffic across 239 guest articles was only 50 visits." The figure is self-reported referral traffic from guest articles, not a count of tagged placed links. Read it as context for what a placed article can send, not as a promise for any one placement.

For a measure of clicks on links inside article bodies at scale, Piccardi, Redi, Colavizza and West of EPFL, the Wikimedia Foundation and the University of Amsterdam logged every click on an external link from English Wikipedia over one month in 2019, published as a study of clicks on Wikipedia's external links at The Web Conference 2021. Their finding: "the CTR of infobox links (0.90%) vastly exceeded that of links in references (0.03%) and article bodies (0.14%)." These are Wikipedia's own outbound links, not placed links on commercial sites, and the figure is a scale, not a forecast. What a link does for a page beyond visits is covered in the benefits of building backlinks, and the two placement formats are compared in guest posts vs niche edits.

What we report on a placement

You supply the target URL and the anchor text when you order. Before a placement goes out we check the HTTP status code the target URL returns. After publication we check that the page is live, that the link sits in the body copy and that the anchor text and target URL match the order. Only then is the URL reported to the dashboard, where every live URL is listed and can be exported as an unbranded file. The full standard is on our quality assurance page.

Every delivered link has 12-month replacement cover. We report the live URL of each placement; the visits it sends are read in your own Analytics property by the methods above. Counting links rather than visits is covered in how many backlinks do you have, turning visits and rankings into a return figure is in measuring link building ROI, and the scores used to choose a site are in link building metrics.

Frequently asked questions

What is UTM link building?

UTM link building means adding a short tag to the end of the URL inside a placed link, so that Google Analytics reports the visit under the tag's values instead of only under the site it came from. Google's Analytics Help page on URL builders says that when you add parameters to a URL, you should always use utm_source, utm_medium and utm_campaign. The tag is read when someone clicks the link, and the values appear in the Traffic acquisition report. A placed link with no tag still appears in reports, filed under the linking site's name.

Which utm_medium should a placed link use?

A placed link should carry referral as its utm_medium when the visit is meant to stay in the Referral channel, because the default channel group places a manually tagged visit in Referral when the medium is referral, app or link. A medium of your own, such as guest-post, matches no listed rule, so the visit lands in Unassigned unless its source or campaign name matches another rule or a custom channel group is built to match it. Custom channel groups are set in Admin, under Data display, Channel groups.

Can a UTM tag go on a backlink?

A UTM tag goes on a backlink through the URL supplied for the link, because the URL inside a placed link is the one given by whoever orders or pitches it. With us, the target URL is supplied when the order is placed, so if you want a tag on a backlink, ask us before you order. When a tagged URL is clicked, Google Analytics files the visit under the tag's values, and the linking page sets the source only when no tag values are present, so a tag replaces what Analytics would have read from the linking page.

Where do I see visits from a placed link in GA4?

Visits from a placed link appear in the Traffic acquisition report, under Reports and then Acquisition in Google Analytics 4. For an untagged link, the Session source dimension carries the linking site and the Session medium reads referral. For a tagged link, the Session campaign dimension carries the campaign value from the tag. Session-scoped dimensions use the paid and organic channels last click model, so each session is credited to one traffic source.