What are UTM parameters?

UTM parameters, explained

Google Analytics' help lists the parameters GA4 supports: utm_source (the referrer, like producthunt or newsletter), utm_medium (the channel, like email, social or cpc), utm_campaign (the campaign name), utm_term (paid keywords), utm_content (to tell apart links or creatives), plus utm_id, utm_source_platform, utm_creative_format and utm_marketing_tactic. It says you should always use utm_source, utm_medium and utm_campaign.

Values are case-sensitive: utm_source=Newsletter and utm_source=newsletter show up as two sources. Pick lowercase and write down your naming rules once, so every teammate tags links the same way. Decide, for example, whether X is x or twitter, and stick to it. GA4 also uses utm_medium when assigning default channel groups, so non-standard mediums can push traffic into "Unassigned".

Use UTMs on links you place outside your site: launch posts, directory listings where allowed, newsletters, social bios, partner links and ads. Never use them on internal links. An internal UTM link starts a new session with the wrong source and overwrites where the visitor really came from.

For SEO, UTMs create extra URL variants of your pages. That's harmless as long as your pages have self-referencing canonicals without parameters, so /?utm_source=newsletter consolidates to /. Search Console will then list those variants as alternates, which is expected. A shared spreadsheet or a UTM builder with fixed options keeps the naming consistent as more people send links.

Why it matters for founders

On launch week, links go out through many channels at once. Tagged links tell you which ones brought users, not just visits.

Example

Your launch newsletter links to /pricing?utm_source=newsletter&utm_medium=email&utm_campaign=launch-2026-09. In GA4 you can see signups from that email separately from social.

Common mistakes

• UTM tags on internal links.
• Inconsistent capitalization across campaigns.
• Missing utm_medium, so traffic lands in the wrong channel.
• Pages without canonicals, so tagged URLs get indexed.