It catches capitalised keys like UTM_Source, values with spaces or capitals, duplicated tags, missing required fields and mediums that Google Analytics 4 files as Unassigned. One click loads the link into the builder so you can fix it.
How to build a UTM link
Paste the page you want people to land on into Website URL. Fill in the three required fields: source is where the link lives, such as newsletter, facebook or partner-blog; medium is the type of traffic, such as email, cpc, social or referral; and campaign is the promotion it belongs to, such as fall-sale-2026. Add content to tell apart two links in the same email or ad, term for paid search keywords, and an ID if you import campaign costs. UTMTidy writes the tagged URL as you type, so you can copy it straight into your email tool, ad manager or social scheduler.
Keep Lowercase ticked and spaces converted to dashes unless you have a different house style. Analytics tools are case-sensitive and treat every variation as a separate row, which is the most common reason campaign reports look fragmented.
Mediums that map to GA4 channels
Google Analytics 4 uses medium and source to sort sessions into default channel groups. Values such as email, cpc, ppc, paid, display, banner, cpm, affiliate, referral, organic, social, paid_social, sms, push, video and audio are recognised. Anything else may end up under Unassigned, so UTMTidy warns you before you share the link. If you have a good reason to use a custom medium, set up a custom channel group in your analytics property.
A registry for consistent names
Press Save to registry after building a link and UTMTidy remembers its source, medium and campaign. Next time, the saved names appear as suggestions and as one-click chips, so the whole team spells the spring campaign the same way. The last twenty links you saved are listed as well, which makes it easy to find the link you sent last week.
Private by design
UTMTidy has no accounts and never sends your URLs anywhere. Links are built and checked with your browser’s own URL parser, and the registry is saved in local storage on this device only.
Frequently asked questions
Why is my campaign traffic showing as Unassigned?
Usually because utm_medium is not a value GA4 recognises. Use standard mediums like email, cpc, social or referral.
Are UTM keys case-sensitive?
Yes. utm_source works; UTM_Source is a different, unrecognised parameter in most tools.
Does the checker visit the link?
No. It only reads the text you paste; nothing is requested from the site.
Is UTMTidy free?
Yes. Building, bulk tagging and checking links is free with no sign-up.
Are my links stored online?
No. Your registry and recent links are saved only in this browser on this device.