UTM parameters and campaign tracking
What the five utm tags mean, how analytics reads them, and naming conventions that keep your channel reports clean and comparable.
What UTM tags actually do
UTM parameters are ordinary query-string values, prefixed with utm_, that ride along on a link. When someone clicks a tagged URL and lands on your site, your analytics tool reads those values and files the visit under the source, medium, and campaign you specified. Nothing about the destination page changes; the tags are simply metadata that turns an anonymous click into an attributable one. That is why a link without them often shows up as direct or unassigned traffic.
The three required tags and two optional ones
Source, medium, and campaign are the backbone. Source names the referrer such as newsletter or google, medium names the channel type such as email or cpc, and campaign names the specific push such as spring_sale. The two optional tags add detail: term is a holdover from paid search for the matched keyword, and content separates two links that point to the same page, which is ideal for A/B testing a headline link against a button. This tool requires the first three and quietly omits the optional pair when they are empty.
Why encoding and structure matter
A campaign value like spring sale contains a space, which is illegal in a raw URL, so it is encoded to spring%20sale before being appended. The builder also respects a URL that already has a query string by joining with an ampersand instead of a second question mark, and it slides the parameters in ahead of any #fragment. These rules prevent a subtle class of bugs where a hand-edited link silently drops a parameter or breaks an in-page anchor, which would leave gaps in your reporting.
A naming convention that scales
The tags are only as useful as they are consistent. Decide once whether values are lowercase, whether words are joined with underscores or hyphens, and what vocabulary you use for each medium, then document it so everyone builds links the same way. Most platforms are case sensitive, so Email and email split into two rows and dilute your numbers. A short shared spreadsheet of approved sources and mediums, paired with this builder, keeps months of campaign data comparable instead of a tangle of near-duplicates.