UTM Builder and Naming Checker

A free tool for anyone tagging campaign links. Build a UTM-tagged link and see which GA4 channel it will land in, and why. Or paste a whole sheet of links to check them together and download the result as a CSV. It runs in your browser; nothing you enter is sent anywhere.

What it builds

Links with utm_source, utm_medium and utm_campaign, plus campaign ID, source platform, content and term, as Google's URL builders: Collect campaign data with custom URLs page describes. Google says to always set the first three; if one is missing, reports show (not set). Google also strongly recommends campaign ID and source platform where they apply. The tool keeps any other query parameters, puts the tags before any #fragment, and leaves ad platform macros such as {keyword} unencoded.

Which GA4 channel each link lands in

The tool runs the source, medium and campaign through the manual-traffic rules on Google's [GA4] Default channel group page, in the order Google lists them, taking the first rule that matches. Google's Custom channel groups page says traffic goes in the first channel it matches; applying that to the default group in Google's listed order is AAJ's reading. Which sources count as search, social, video or shopping comes from Google's source list; the tool knows the common names AAJ checked against it and says when a source isn't one of them.

Mistakes it catches

• Medium "newsletter" lands in Unassigned. Google's Email channel needs medium (or source) email.
• Paid ads tagged with source "meta" or "x" land in Paid Other, not Paid Social, because neither name is on Google's list of social sites. "fb", "ig", "linkedin" and "t.co" are.
• Source "linkedin" with medium "email" counts as Organic Social, because Google lists Organic Social before Email.
• A campaign name containing "shop" counts as Shopping.
• "SpringSale", "spring-sale" and "spring_sale" become separate campaigns. Google says values are case sensitive and recommends lowercase.
• An email address in a UTM value. Google's policy on personally identifiable information bars it from campaign parameters.

The naming convention it checks against (lowercase, hyphens between words, only a-z, 0-9, hyphen, underscore and dot) is AAJ's, and is labelled so. Each check says whether it is Google's rule or AAJ's convention, reading or suggestion.

Why I built a checker, not just a builder

Most UTM builders paste your words into a link and stop. The link works, and the visits still end up in the wrong place. So this tool shows the GA4 channel each link should count as and describes the Google rule behind it.

Limits

• It uses GA4's default channel group for manually tagged traffic. If your property uses a custom channel group, its rules decide instead; Google Ads auto-tagged traffic follows separate rules.
• Google's source list is long; the tool knows the common names AAJ checked, and flags any source it hasn't checked.
• It can't see your ad platform. Check that auto-tagging doesn't overwrite your UTMs.

Check up to 500 links at a time. For what the tagged traffic does next, use the Marketing KPI Report. To ask buyers how they found you, use the Self-Reported Attribution Coder.