Glossary · Traffic sources & UTMs
What is utm_source?
utm_source is the UTM parameter that identifies the specific site, platform or publisher that sent a visit — for example google, newsletter, x or a partner's name.
Also called: UTM source, Campaign source
Updated
How utm_source works
Add utm_source=<name> to a link's query string. When a visitor lands, the analytics script reads it and records that value as the session's source, overriding whatever the referrer said. Source answers "who?"; utm_medium answers "what kind of channel?" Together they form the source/medium pair most reports group by.
| Link placed in | utm_source | utm_medium |
|---|---|---|
| Your weekly newsletter | newsletter | email |
| A post on X | x | social |
| A Google Ads campaign | google | cpc |
| A partner's blog | partnername | referral |
| A podcast sponsorship | podcastname | audio |
utm_source example
You announce a feature in your newsletter and on LinkedIn. With utm_source=newsletter and utm_source=linkedin on the two links, the report shows 820 visits from the newsletter with 31 sign-ups and 410 from LinkedIn with 6. Without tags, most newsletter clicks would have landed in direct.
Naming rules for utm_source
- Use the platform or publisher name, lowercase, no spaces:
producthunt, notProduct Hunt. - Keep one spelling per source forever;
twitterandxside by side split your history — pick one. - Don't encode the channel in the source (
newsletter-email); that's what medium is for. - For individual partners or affiliates, use a stable slug per partner so you can rank them.
How VisitTrack uses utm_source
VisitTrack stores utm_source on each session and shows it in campaign and source breakdowns; the first-touch source is the one credited for revenue. If a landing URL has an ad click id but no utm_source, VisitTrack fills the source with the platform (google for gclid, facebook for fbclid, twitter for twclid, and so on). Build tagged links with the UTM builder.
Frequently asked questions
What is the difference between utm_source and utm_medium?
utm_source names the specific sender (google, newsletter, linkedin); utm_medium names the type of channel (cpc, email, social). Many sources can share one medium.
Is utm_source required?
Treat it as required. Google's own URL builders mark it as required, and without a source the other tags can't be reported in context — it's the most important tag for attributing a visit.
Related terms
- UTM parametersUTM parameters are five standard query-string tags — utm_source, utm_medium, utm_campaign, utm_term and utm_content — added to a link so analytics tools can attribute the visit to a specific source, channel and campaign.
- utm_mediumutm_medium is the UTM parameter that describes the type of marketing channel that sent a visit — such as email, cpc, social, referral or affiliate — and is what most tools use to assign the visit to a channel group.
- utm_campaignutm_campaign is the UTM parameter that names the specific campaign, launch or promotion a link belongs to, so visits and conversions from every channel in that campaign can be grouped together.
- ReferrerA referrer is the address of the web page that linked a visitor to the current page, sent by the browser in the HTTP Referer header and exposed to scripts as document.referrer.
- Channel groupingChannel grouping is the set of rules an analytics tool uses to sort every visit into a marketing channel — such as direct, organic search, paid search, social, email or referral — based on its referrer, UTM parameters and ad click ids.
Tools and guides
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