UTM parameters explained: what utm_source really tells websites
UTM parameters are campaign labels for the site's analytics — utm_source=newsletter means "this visitor came from our newsletter." They're harmless to the page but tell the site (and everyone you forward the link to) exactly where you got it. Safe to delete, always.
The five parameters
| Parameter | Answers | Example |
|---|---|---|
utm_source | Where from? | newsletter, facebook |
utm_medium | What kind of channel? | email, cpc, social |
utm_campaign | Which push? | spring_sale |
utm_term | Which ad keyword? | link+cleaner |
utm_content | Which button/variant? | header_cta |
They date back to the Urchin Tracking Module — the software Google bought and turned into Google Analytics. Twenty years later they're stapled to half the links on the internet.
What forwarding leaks
UTMs don't identify you personally the way a click ID does. The leak is subtler: forward a link tagged utm_source=investor_update or utm_campaign=vip_customers and everyone you send it to can read exactly which list you're on. Meanwhile the site's analytics counts every one of your friends as a "newsletter" visitor — wrong for them, noisy for the site.
When to keep them
One honest case: your own campaigns. If you're the marketer and the link is going into your newsletter, the UTMs are the point. Keep them there — and strip them from everything you share person-to-person.
Stripping them automatically
tdy, a tiny Mac menu-bar app, removes utm_* (and the Matomo/HubSpot/Mailchimp equivalents) from every link you copy, before you paste it anywhere. Every transform is a toggle, so if you're mid-campaign you can pause it or exclude your marketing tools. The full parameter guide covers what else gets cleaned.
Forward links, not labels.
tdy strips utm_ and friends from every link you copy. Native, one-time purchase, no subscription.
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