UTM link builder

What each UTM parameter is for

UTM tags (Urchin Tracking Module, after the analytics product Google bought in 2005) are query parameters that tell your analytics where a visit came from. Google Analytics 4, and most other analytics and CRM tools, read them automatically.

GA4 also accepts utm_source_platform, utm_creative_format and utm_marketing_tactic, but most teams never need them. Get the core three right first.

A naming convention that still works in a year

Most messy analytics comes from inconsistent naming, not missing tags. One person writes Facebook, another fb, a third meta, and your report splits one channel into three rows. Agree a short set of rules and write them down:

• Lowercase everything. UTM values are case-sensitive in GA4.
• Hyphens, not spaces. Spaces become %20 or + and are easy to get wrong.
• A fixed list of mediums. For example cpc, paid-social, email, social, referral, affiliate, display, print. Nobody invents a new one without updating the list.
• One name per source. Decide whether it is facebook or meta, once.
• A campaign pattern. Something like year-quarter-theme, e.g. 2026-q4-black-friday, so campaigns sort and filter cleanly.

The history panel helps here: reuse last month's link and only change what is new, instead of retyping names from memory.

How GA4 turns source and medium into a channel

GA4's default channel group sorts every session into channels such as Paid Search, Organic Social or Email, using rules on source, medium and campaign name. Your medium choice matters more than anything else:

‘Paid’ means a medium matching GA4's paid pattern: anything containing cp (cpc, cpm, cpv), ppc, retargeting, or starting with paid. A paid medium with a source GA4 doesn't recognise lands in Paid Other. The hint in the builder applies a simplified version of these rules; GA4's real source lists are much longer, so treat it as a guide.

Getting more from utm_content and utm_term

Source, medium and campaign tell you where traffic came from; the two optional tags tell you what worked. utm_content separates links that share a campaign: the header button versus the footer link in the same newsletter, or two ad creatives in one ad set. Name the variant, not the date, for example hero-video and hero-static, so a report reads like an experiment result. utm_term was built for paid keywords; with auto-tagged search ads you rarely need it, but it is handy for audience names on paid social, such as lookalike-1pc.

The Bulk tab is built for exactly this: list your content variants or landing pages one per line, keep the campaign tags identical, and export the lot as a CSV for your ad platform or campaign log. Keeping that log, even a simple spreadsheet of every tagged link and where it was used, is what makes the numbers trustworthy six months later.

Mistakes that quietly break attribution

• Tagging internal links. It overwrites the real source of the visit. Never tag links between your own pages.
• Tags after the #. Anything after a fragment never reaches the server, so the tags vanish.
• Redirects that drop the query string. Test the final link; some redirects and link-in-bio tools strip parameters.
• Double tagging. Pasting a link that already has UTMs and adding more creates duplicates. The builder replaces matching tags and offers to remove the rest.

Before a campaign link goes out, it is also worth checking how the page looks when shared, with the Open Graph preview, and how it appears in search, with the SERP snippet preview. Testing two landing pages against each other? Size the test with the A/B test calculator. Every site I build through website design ships with analytics wired correctly from launch day.